source3/script: Fix installation of winbind_ctdb_updatekeytab.sh

source3/script: Fix installation of winbind_ctdb_updatekeytab.sh

winbind_ctdb_updatekeytab.sh assumes the presence `onnode` utility to
execute `net ads` command on all nodes in the cluster. But `onnode`
is only built when configured with clustering support. Therefore perform
the script installation only with ctdb configuration. Also fix the
installation path to /usr/share/ctdb/scripts.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15689
Signed-off-by: Anoop C S <anoopcs@samba.org>
Reviewed-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Guenther Deschner <gd@samba.org>
Reviewed-by: Pavel Filipenský <pfilipensky@samba.org>
(cherry picked from commit 3929fdae1a13ab029e173ce53598d3fa6cf40e9c)