Switch from balancing across backends based on source ip address
hash to least number of connections.
Because we have git repos of many sizes, some of which take seconds
to clone, others minutes, we can end up with a load imbalance across
our git backends. Further, organizations that use NAT to put a
large number of systems behind a single IP address further exacerbate
the imbalance. Switch to least-connections for load balancing to
better utilize our backends, and hopefully smooth peak loads across
them.
Change-Id: I7ea5e2ff0c98c46237a975989bd014149de01b04
6af76957e5