Fix error reporting for fetch_key (#2662)

Since fetch_url already take care of the exception, the try/except
clause is no longer working, so replace it with proper status
checking, thus permitting to remove urlib2 from the import list.

lib/ansible/modules/packaging/os/rpm_key.py

@@ -62,7 +62,6 @@ EXAMPLES = '''
 '''
 import re
 import os.path
-import urllib2
 import tempfile
 
 def is_pubkey(string):
@@ -115,18 +114,18 @@ class RpmKey:
 
     def fetch_key(self, url):
         """Downloads a key from url, returns a valid path to a gpg key"""
-        try:
-            rsp, info = fetch_url(self.module, url)
-            key = rsp.read()
-            if not is_pubkey(key):
-                self.module.fail_json(msg="Not a public key: %s" % url)
-            tmpfd, tmpname = tempfile.mkstemp()
-            tmpfile = os.fdopen(tmpfd, "w+b")
-            tmpfile.write(key)
-            tmpfile.close()
-            return tmpname
-        except urllib2.URLError, e:
-            self.module.fail_json(msg=str(e))
+        rsp, info = fetch_url(self.module, url)
+        if info['status'] != 200:
+            self.module.fail_json(msg="failed to fetch key at %s , error was: %s" % (url, info['msg']))
+
+        key = rsp.read()
+        if not is_pubkey(key):
+            self.module.fail_json(msg="Not a public key: %s" % url)
+        tmpfd, tmpname = tempfile.mkstemp()
+        tmpfile = os.fdopen(tmpfd, "w+b")
+        tmpfile.write(key)
+        tmpfile.close()
+        return tmpname
 
     def normalize_keyid(self, keyid):
         """Ensure a keyid doesn't have a leading 0x, has leading or trailing whitespace, and make sure is lowercase"""