Sync latest openstack-common.
Sync latest openstack-common.

This fixes an issue when trying to run install_venv from within
the source directory.

Change-Id: Id4dcb070319ec52d0a1b466e911fbfdf805db613

dtroyer/python-openstackclient,hughsaunders/python-openstackclient,varunarya10/python-openstackclient,BjoernT/python-openstackclient,citrix-openstack-build/python-openstackclient,redhat-openstack/python-openstackclient,metacloud/python-openstackclient,metacloud/python-openstackclient,derekchiang/python-openstackclient,redhat-openstack/python-openstackclient,BjoernT/python-openstackclient,citrix-openstack-build/python-openstackclient,openstack/python-openstackclient,derekchiang/python-openstackclient,dtroyer/python-openstackclient,varunarya10/python-openstackclient,hughsaunders/python-openstackclient,openstack/python-openstackclient