Swift doesn't recommend any rsync hostname allow/deny rules for inside
your cluster network and I've never heard of anyone using it. The
reverse lookup on connect (even those denied for max connections) can be
overwhelming during a rebalance. Since rsync allows explicit control of
the behavior after 3.1 we should suggest operators use it, It's also
nominally more efficient in all cases. Possible drawback is maybe in
the future a Swift operator has good reason to use host allow/deny rules
and don't realize the rsync settings we recommend are mutually exclusive
with their customizations.
Change-Id: I2fdffdf1cc0a77f994c1d7894d5a1c8e5d951755