ctdb-tests: Ensure ss stub handles square brackets around addresses

It isn't unreasonable for unit test cases to use square brackets in
their input.

Signed-off-by: Martin Schwenke <mschwenke@ddn.com>
Reviewed-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jerry Heyman <jheyman@ddn.com>

ctdb/tests/UNIT/eventscripts/stubs/ss

@@ -83,6 +83,8 @@ filter_socket()
 	socket="$3"
 
 	ip="${socket%:*}"
+	ip="${ip#\[}"
+	ip="${ip%\]}"
 	port="${socket##*:}"
 
 	if [ "$ok_ports" != "|" ] &&