Fix Django 1.7 compat

In Debian, we are going to release Jessie with Django 1.7,
which has just been released. Therefore, compatibility is
important for us.

This patch, which the Debian package already carries, fixes
2 small compatibility issues with Django 1.7. It is safe to
use openstack_auth with these patches and a lower version of
Django, which makes it safe to apply this patch.

Change-Id: I564cde889c56e12fc0fc1347537e66b576605a0d
Merge "Fix Django 1.7 compat"