Updated openstack/openstack
Project: openstack-dev/devstack  3148d8a7130ff4af954ba2be566a15ef8ee6273c

neutron: use non-deprecated notification_driver

Neutron is now using oslo.messaging so it should be
using 'messaging' as its notification driver and not the now deprecated
full python path to the oslo-incubator notification driver.

Change-Id: Ie4a4020e59473473ad62059c66507f5b73b93375