Make the keycloak middleware thread safe
Make the keycloak middleware thread safe

After moving to uWSGI keycloak middleware was found to be not
thread safe since we hold the token nad relam in an attribute
of a class which initialized once.
So if there are several threads
accessing the class there might have race conditions
lets move them to be parameters on the stack

Change-Id: I5325c7f08f6567d46189d4efdfbc9b0f6f5a8916

openstack/vitrage,openstack/vitrage,openstack/vitrage