Use SERVICE_PROTOCOL variable in the devstack plugin
Use SERVICE_PROTOCOL variable in the devstack plugin

Vitrage service be deployed with TLS in Devstack, so we need to honor
SERVICE_PROTOCOL variable to set correct value for VITRAGE_SERVICE_PROTOCOL

Change-Id: Ic22be897e255bb19f17009fbc38ca282273f3c95

openstack/vitrage,openstack/vitrage,openstack/vitrage