Update hconfd bind address handling

Instead of hardcoded IPv4 INADDR_ANY, this patch changes hconfd to use
either the any network for the configured cluster address family
(ipv4/ipv6), or whatever the user passes in via the --bind option.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>