Correct concurrency of gabbi tests for gabbi 1.22.0
Correct concurrency of gabbi tests for gabbi 1.22.0

When running gabbi under testr, concurrency grouping is controlled
by a regex in .testr.conf. A module name change in gabbi 1.22.0
inadvertently broke the grouping. This change should work for
old and new versions.

Change-Id: I4edcc19738bc01e6b45eeeb287d0583a14f6f50c

openstack/ceilometer,ityaptin/ceilometer,openstack/ceilometer,ityaptin/ceilometer