ctdb-daemon: Use ctdb_connection_to_buf() to simplify

ctdb-daemon: Use ctdb_connection_to_buf() to simplify

The one case that is no longer handled specially is when the
destination address is IPv4 loopback.  This may previously have been
used to avoid flooding the logs when testing.  However, that seems
unnecessary - if testing with 127.0.0.1 then make it a public address.

Modernise debug while touching the code.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15523

Signed-off-by: Martin Schwenke <mschwenke@ddn.com>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
(cherry picked from commit 8fc3872557f715dc38f9898754a785fd073ace96)