Mark Active-Active mode as supported
Mark Active-Active mode as supported

Since we've got multinode job with Active/Active HA configured we can
remove 'unsupported' message from the 'cluster' config option.

Change-Id: Ida2b025eb34e6745dd5f37fbd20b74e1c96f3ca7

openstack/cinder,openstack/cinder,mahak/cinder,mahak/cinder