Fixed keystone cache vip for dogpile

The keystone cache vip was being pinned to the internal lb vip address
this causes issues with consistant hashing in caches and removes the
requirement for having memcached on a vip address powered by the
LB.

Change-Id: I6aaecbbf0ebf5aa2433d68e8c139ddfff810c973
Closes-Bug: 1398649
Merge "Fixed keystone cache vip for dogpile"