ios_config will now explicitly disconnect from remote host (#5247)

The ios_config module will now explicitly send a disconnect to the
remote host at the conclusion of the module run

ref #5181

lib/ansible/modules/network/ios/ios_config.py

@@ -322,8 +322,10 @@ def main():
         run(module, result)
     except NetworkError:
         exc = get_exception()
+        module.disconnect()
         module.fail_json(msg=str(exc))
 
+    module.disconnect()
     module.exit_json(**result)