s3-vfs_glusterfs: always disable write-behind translator

s3-vfs_glusterfs: always disable write-behind translator

The "pass-through" option has now been merged upstream as of:
https://github.com/gluster/glusterfs/pull/1640

BUG: https://bugzilla.samba.org/show_bug.cgi?id=14486

Guenther

Signed-off-by: Guenther Deschner <gd@samba.org>
Pair-Programmed-With: Anoop C S <anoopcs@samba.org>
Pair-Programmed-With: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Jeremy Allison <jra@samba.org>
Autobuild-User(master): Jeremy Allison <jra@samba.org>
Autobuild-Date(master): Wed Nov  4 22:53:49 UTC 2020 on sn-devel-184