Fix access_ip_* race

The code currently sets access_ip_* in a 2nd DB call after an instance
goes ACTIVE, which means there's a slight race when someone is querying
the API for their instance.  It's possible to see the instance ACTIVE but
access_ip_* will be blank.

To fix this, we should set access_ip_* at the same time the instance goes
ACTIVE.  This also removes an unnecessary extra DB call.

Fixes bug 1152328

Change-Id: I0fe542d49fbc95f27a24f57f674264f8789bc527