Catch ConnectionForced Exception

Occasionally I saw large number of connectionforced exceptions.
such exceptions cannot be healed automatically and requires a reboot.
catch it and ensure connection established.

Changes:
  oslo_messaging/_drivers/impl_rabbit.py

NOTE(stephenfin): We need to add the 'absolute_import' future to disable
the legacy import flow. Without this, the import of 'amqp.exceptions' in
'oslo_messaging._drivers.impl_rabbit' attempts to import 'exceptions'
from the sibling module, 'oslo_messaging._drivers.amqp', instead of the
top-level 'amqp' module. Thank God for Python 3.x, eh? More information
is available at [1], for those curious enough.

[1] https://stackoverflow.com/q/33743880/

Change-Id: I5c468d10230f05438df780e045f1e92662edf070
Closes-Bug: #1883038
(cherry picked from commit 26e8bb4cc9)
(cherry picked from commit 360deb89a7)

oslo_messaging/_drivers/impl_rabbit.py

@@ -12,6 +12,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from __future__ import absolute_import
+
 import contextlib
 import errno
 import functools
@@ -26,6 +28,7 @@ import threading
 import time
 import uuid
 
+from amqp import exceptions as amqp_exec
 import kombu
 import kombu.connection
 import kombu.entity
@@ -1036,7 +1039,8 @@ class Connection(object):
                     except (socket.timeout,
                             ConnectRefuseError,
                             OSError,
-                            kombu.exceptions.OperationalError) as exc:
+                            kombu.exceptions.OperationalError,
+                            amqp_exec.ConnectionForced) as exc:
                         LOG.info("A recoverable connection/channel error "
                                  "occurred, trying to reconnect: %s", exc)
                         self.ensure_connection()