Enable xtrace for devstack plugin
Enable xtrace for devstack plugin

Change-Id: I5a9761bd0a08ead2b812e0eb87fd98f0b95e16d9

openstack/networking-bagpipe-l2,openstack/networking-bagpipe,stackforge/networking-bagpipe-l2,stackforge/networking-bagpipe-l2,openstack/networking-bagpipe,openstack/networking-bagpipe-l2