Updated openstack/openstack
Project: openstack/tempest  67f80914de1a51984b0d609bdfc9b3bd93e2ff0c

Fix resource cleanup in server rescue tests

If server rescue tests are skipped then the resource cleanup method
terminates with AttributeError: type object has no attribute 'volume'.
The fix checks whether volume exist before operating with it.

Change-Id: I6ae7f7bb2ba73313db676bafd597c0934704959a