Handle keystoneauth exceptions in retry logic

The retry_logic in do_request catches neutronclient errors, but if a
SessionClient is being used, nothing throws neutronclient errors -
instead keystoneauth Session throws keystoneauth exceptions.

Add the keystoneauth.exceptions.ConnectionError to the things that
handle the error and retry.

Change-Id: If16e50ee53279652fbdfc2d13d5509f46a54124a
(cherry picked from commit b8a05333dd)

neutronclient/v2_0/client.py

@@ -22,6 +22,7 @@ import re
 import time
 
 import debtcollector.renames
+from keystoneauth1 import exceptions as ksa_exc
 import requests
 import six.moves.urllib.parse as urlparse
 from six import string_types
@@ -335,7 +336,7 @@ class ClientBase(object):
             try:
                 return self.do_request(method, action, body=body,
                                        headers=headers, params=params)
-            except exceptions.ConnectionFailed:
+            except (exceptions.ConnectionFailed, ksa_exc.ConnectionError):
                 # Exception has already been logged by do_request()
                 if i < self.retries:
                     _logger.debug('Retrying connection to Neutron service')