Use direct gerrit contactstore to avoid CDN issues

* modules/openstack_project/manifests/review.pp: The foundation
member API backend now has a separate direct hostname which can be
used to connect to it without going through a CDN. Using it will
work around proxy-related throttle problems we've seen in the past
where the CDN decides it's being attacked by our Gerrit when failing
arbitrary contact store updates.

Change-Id: I5387eb0d28e8e990ddfa04af9ce8f07468c0f0d6
Merge "Use direct gerrit contactstore to avoid CDN issues"