'module' object has no attribute 'DeprecationWarning'

[Kai Qiang Wu(Kennan)]

in our jenkins job found failure with this

Traceback (most recent call last):

  File "/usr/local/lib/python2.7/dist-packages/wsmeext/pecan.py", line 84, in callfunction
    result = f(self, *args, **kwargs)

  File "<decorator-gen-4>", line 2, in patch

  File "/opt/stack/new/magnum/magnum/api/validation.py", line 90, in wrapper
    baymodel = api_utils.get_rpc_resource('BayModel', baymodel_ident)

  File "/opt/stack/new/magnum/magnum/api/controllers/v1/utils.py", line 75, in get_rpc_resource
    return resource.get_by_uuid(pecan.request.context, resource_ident)

  File "/usr/local/lib/python2.7/dist-packages/oslo_versionedobjects/base.py", line 173, in wrapper
    args, kwargs)

  File "/usr/local/lib/python2.7/dist-packages/oslo_versionedobjects/base.py", line 985, in object_class_action_versions
    'in a later release', warnings.DeprecationWarning)

AttributeError: 'module' object has no attribute 'DeprecationWarning'

[Kai Qiang Wu(Kennan) (wkqwu)]

https://review.openstack.org/#/c/246721/