Make HS ConfD client IPv6 compatible

The Haskell ConfD client was assuming internet addresses to be IPv4. This
patch modifies the client so that it is able to automatically detect the
protocol it should use by analyzing the address it is told to connect to.

Signed-off-by: Michele Tartara <mtartara@google.com>
Reviewed-by: Helga Velroyen <helgav@google.com>