s3:cluster: fix ctdb ipv6 support

s3:cluster: fix ctdb ipv6 support

We need to use CTDB_CONTROL_TCP_CLIENT instead of CTDB_CONTROL_TCP_ADD.

CTDB_CONTROL_TCP_CLIENT has support for 2 modes in newer ctdb versions:

- with struct ctdb_control_tcp it only supports ipv4.
- with struct ctdb_control_tcp_addr it supports ipv4 and ipv6.

You need new header files which defines struct ctdb_control_tcp_addr,
but at runtime it should be fine to work against older
ctdb versions (<= 1.0.68).

metze
(cherry picked from commit dc6edf1ab4ae8e3fb3ef40b93135ff0ef5407e12)