Fixing import error in the vcenter setups. Both keystoneclient.middleware and keystonemiddleware modules will not be available.use in setups with vcenter as orchestrator.
Fixing import error in the vcenter setups. Both keystoneclient.middleware and
keystonemiddleware modules will not be available.use in setups with vcenter
as orchestrator.

Change-Id: Ided2ca15faf4a58d35c135e5e9397d9764b34fc9
Closes-Bug: 1558301

codilime/contrail-controller,nischalsheth/contrail-controller,rombie/contrail-controller,nischalsheth/contrail-controller,eonpatapon/contrail-controller,codilime/contrail-controller,nischalsheth/contrail-controller,rombie/contrail-controller,eonpatapon/contrail-controller,codilime/contrail-controller,codilime/contrail-controller,rombie/contrail-controller,nischalsheth/contrail-controller,rombie/contrail-controller,codilime/contrail-controller,rombie/contrail-controller,eonpatapon/contrail-controller,eonpatapon/contrail-controller,rombie/contrail-controller,nischalsheth/contrail-controller,nischalsheth/contrail-controller,nischalsheth/contrail-controller,rombie/contrail-controller,eonpatapon/contrail-controller,eonpatapon/contrail-controller,eonpatapon/contrail-controller,codilime/contrail-controller,nischalsheth/contrail-controller