Updated openstack/openstack
Project: openstack/neutron  7929b6e2b920bc69e1e008270f4b0d325efd0479
null
improve UT coverage for nicira_db operations

Also, ensure that a rollback is issued in the
event of any DB error.

Change-Id: I706db09f11fb5f6b369a1bd0cb1016df7d0359b5
Related-bug: #1265472