Fix os_region in example session
Fix os_region in example session

Change-Id: I919ceb923dce44a1029facea4e93d1e9a1421dc1

stackforge/python-openstacksdk,dudymas/python-openstacksdk,briancurtin/python-openstacksdk,mtougeron/python-openstacksdk,mtougeron/python-openstacksdk,openstack/python-openstacksdk,dudymas/python-openstacksdk,dtroyer/python-openstacksdk,dtroyer/python-openstacksdk,openstack/python-openstacksdk,stackforge/python-openstacksdk,briancurtin/python-openstacksdk