Network F5: Adjust for Python 3 scoping rules (#37554)

This PR makes and adjustment for Python 3 scoping rules which differ from Python 2.  In Python 3, the variable __ex__ goes out of scope at the exit of the __try-except__ block.  This means that when __ex__ is referred to on the lines that follow, it would be an _undefined name_ causing a __NameError__ to be raised instead of the expected __ConnectionError__.

flake8 testing of https://github.com/ansible/ansible on Python 3.6.3
The command "echo ; echo -n "flake8 testing of ${URL} on " ; python -V" exited with 0.
130.72s$ time flake8 . --count --select=E901,E999,F821,F822,F823 --show-source --statistics
./lib/ansible/module_utils/api.py:114:21: F823 local variable 'retry_count' (defined in enclosing scope on line 107) referenced before assignment
                    retry_count += 1  # pylint: disable=undefined-variable
                    ^
./lib/ansible/module_utils/six/__init__.py:54:20: F821 undefined name 'basestring'
    string_types = basestring,
                   ^
./lib/ansible/module_utils/six/__init__.py:55:27: F821 undefined name 'long'
    integer_types = (int, long)
                          ^
./lib/ansible/module_utils/six/__init__.py:57:17: F821 undefined name 'unicode'
    text_type = unicode
                ^
./lib/ansible/module_utils/six/__init__.py:658:16: F821 undefined name 'unicode'
        return unicode(s.replace(r'\\', r'\\\\'), "unicode_escape")
               ^
./lib/ansible/module_utils/six/__init__.py:754:37: F821 undefined name 'basestring'
            if not isinstance(data, basestring):
                                    ^
./lib/ansible/module_utils/six/__init__.py:757:32: F821 undefined name 'file'
            if (isinstance(fp, file) and
                               ^
./lib/ansible/module_utils/six/__init__.py:758:38: F821 undefined name 'unicode'
                    isinstance(data, unicode) and
                                     ^
./lib/ansible/module_utils/six/__init__.py:768:32: F821 undefined name 'unicode'
            if isinstance(sep, unicode):
                               ^
./lib/ansible/module_utils/six/__init__.py:774:32: F821 undefined name 'unicode'
            if isinstance(end, unicode):
                               ^
./lib/ansible/module_utils/six/__init__.py:782:36: F821 undefined name 'unicode'
                if isinstance(arg, unicode):
                                   ^
./lib/ansible/module_utils/six/__init__.py:786:23: F821 undefined name 'unicode'
            newline = unicode("\n")
                      ^
./lib/ansible/module_utils/six/__init__.py:787:21: F821 undefined name 'unicode'
            space = unicode(" ")
                    ^
./lib/ansible/modules/cloud/misc/rhevm.py:594:24: F821 undefined name 'e'
            setMsg(str(e))
                       ^
./lib/ansible/modules/cloud/openstack/os_user.py:202:38: F821 undefined name 'shade'
    if description and StrictVersion(shade.__version__) < StrictVersion('1.13.0'):
                                     ^
./lib/ansible/modules/cloud/openstack/os_volume.py:153:27: F821 undefined name 'shade'
            StrictVersion(shade.__version__) < StrictVersion('1.22')):
                          ^
./lib/ansible/modules/files/archive.py:391:92: F821 undefined name 'e'
                module.fail_json(dest=dest, msg='Error deleting some source files: ' + str(e), files=errors)
                                                                                           ^
./lib/ansible/modules/network/dellos9/dellos9_facts.py:379:24: F821 undefined name 'key'
                parsed[key] += '\n%s' % line
                       ^
./lib/ansible/modules/network/dellos9/dellos9_facts.py:399:24: F821 undefined name 'key'
                parsed[key] += '\n%s' % line
                       ^
./lib/ansible/modules/network/dellos9/dellos9_facts.py:403:24: F821 undefined name 'key'
                parsed[key] += '\n%s' % line
                       ^
./lib/ansible/modules/network/dellos9/dellos9_facts.py:418:24: F821 undefined name 'key'
                parsed[key] += '\n%s' % line
                       ^
./lib/ansible/modules/network/f5/bigip_device_httpd.py:461:40: F821 undefined name 'ex'
        if 'Connection aborted' in str(ex) and 'redirectHttpToHttps' in params:
                                       ^
./lib/ansible/modules/network/f5/bigip_device_httpd.py:465:33: F821 undefined name 'ex'
        raise F5ModuleError(str(ex))
                                ^
./lib/ansible/modules/network/ironware/ironware_facts.py:274:24: F821 undefined name 'key'
                parsed[key] += '\n%s' % line
                       ^
./lib/ansible/modules/network/ironware/ironware_facts.py:514:24: F821 undefined name 'key'
                parsed[key] += '\n%s' % line
                       ^
24    F821 undefined name 'basestring'
1     F823 local variable 'retry_count' (defined in enclosing scope on line 107) referenced before assignment
25

lib/ansible/modules/network/f5/bigip_device_httpd.py

@@ -454,15 +454,13 @@ class ModuleManager(object):
             resource.modify(**params)
             return True
         except ConnectionError as ex:
-            pass
-
-        # BIG-IP will kill your management connection when you change the HTTP
-        # redirect setting. So this catches that and handles it gracefully.
-        if 'Connection aborted' in str(ex) and 'redirectHttpToHttps' in params:
-            # Wait for BIG-IP web server to settle after changing this
-            time.sleep(2)
-            return True
-        raise F5ModuleError(str(ex))
+            # BIG-IP will kill your management connection when you change the HTTP
+            # redirect setting. So this catches that and handles it gracefully.
+            if 'Connection aborted' in str(ex) and 'redirectHttpToHttps' in params:
+                # Wait for BIG-IP web server to settle after changing this
+                time.sleep(2)
+                return True
+            raise F5ModuleError(str(ex))
 
     def read_current_from_device(self):
         resource = self.client.api.tm.sys.httpd.load()