Updated openstack/openstack
Project: openstack/nova  5895d3e6f211444c4041827f0371a1b7c786e678

Fix DB migration 254 by adding missing unittest

By merging https://review.openstack.org/#/c/114286/23, a new db migration
was added but the unittest was missing.

Change-Id: I32e2455fd5efb2aad52d9a4d7666783c0e613e75