[vnc_openstack]: Fix to raise correct err msg

Tempest test 'test_network_quota_exceeding' expects Confict exception
with ['network'] instead of u'virtual_network'. This patch fixes this
error message.

Change-Id: I41137290ee851746a7ec1aa041fe54cf29ccec21
Closes-Bug: #1712773
(cherry picked from commit f7e7d20)

src/config/vnc_openstack/vnc_openstack/neutron_plugin_db.py

@@ -82,6 +82,10 @@ def get_uuid(self):
         return self.uuid
 
 
+# VNC to neutron resource type
+_RESOURCE_VNC_TO_NEUTRON = {'virtual_network':
+                            'network'}
+
 class LocalVncApi(VncApi):
     def __init__(self, api_server_obj, *args, **kwargs):
         if api_server_obj:
@@ -637,6 +641,8 @@ def _resource_create(self, resource_type, obj):
             self._raise_contrail_exception('BadRequest',
                                            resource=resource_type, msg=str(e))
         except OverQuota as e:
+            if resource_type in _RESOURCE_VNC_TO_NEUTRON:
+                resource_type = _RESOURCE_VNC_TO_NEUTRON[resource_type]
             self._raise_contrail_exception('OverQuota',
                                            overs=[resource_type], msg=str(e))
         except AuthFailed as e: