contrail raises wrong quota exception

This patch reraise OverQuota exception which
come from contrail.

In kilo and Liberty, OverQuota exception is defined
in neutron/common/exceptions.py.In Mitaka, it moved
to neutron_lib project neutron_lib/exceptions.py#L212

Change-Id: I92a8f36709f0f44eece2cff7afa5fcde2edc413e
Closes-Bug: #1590930

neutron_plugin_contrail/plugins/opencontrail/contrail_plugin.py

@@ -46,6 +46,11 @@
 except ImportError:
     from oslo_log import log as logging
 
+try:
+    from neutron_lib import exceptions as libexc
+except ImportError:
+    libexc = None
+
 from simplejson import JSONDecodeError
 from cfgm_common import utils as cfgmutils
 
@@ -322,6 +327,8 @@ def _raise_contrail_error(self, info, obj_name):
                 raise getattr(securitygroup, exc_name)(**info)
             if hasattr(allowedaddresspairs, exc_name):
                 raise getattr(allowedaddresspairs, exc_name)(**info)
+            if libexc and hasattr(libexc, exc_name):
+                raise getattr(libexc, exc_name)(**info)
         raise exc.NeutronException(**info)
 
     def _create_resource(self, res_type, context, res_data):