Fix legacy clients helpers
Fix legacy clients helpers

There is no method called _create_or_return_legacy_client.

Also, you have to pass a variable to a format.

Change-Id: I559416d29c34b6cfea944f405c8608714ad81508

stackforge/python-openstacksdk,openstack/python-openstacksdk,openstack/python-openstacksdk,openstack-infra/shade,stackforge/python-openstacksdk,dtroyer/python-openstacksdk,openstack-infra/shade,dtroyer/python-openstacksdk