Fix url from stackforge to openstack
Fix url from stackforge to openstack

The project has been move from stackforge to openstack, so modify
it.

Closes-Bug: #1547304
Change-Id: I4d0133e91071f42a01adcc4ac5cc7c76f810cf7d

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