Updated openstack/openstack
Project: openstack-dev/devstack  fa893dbb49025943186c54507a26fbb8c7f8413c

XenAPI: Always update apt sources

If an appliance is used as a base OS, the user might want to use that in
a different region. With this change we always update the used mirrors
in the template.

Change-Id: I7a119664efac1124e54064311c243c63c2a7944b