Get auth opts from appropriate getter
Get auth opts from appropriate getter

keystonemiddleware team has moved the calculation of auth opts from
keystonemiddleware.opts to keystonemiddleware.auth_token [1], so that we can
no longer access it directly, we should do it by the appropriate getter.
Conform to it.

[1] If67d8bdb68a5ab9c07b960ad0111e2310ad82c83

Change-Id: I17afd43998ef61279f3f133cc8d6a7e0d6d1324b

openstack/freezer-api,szaher/freezer-api,openstack/freezer-api,szaher/freezer-api,openstack/freezer-api,openstack/freezer-api,szaher/freezer-api,szaher/freezer-api