Fix for https://bugzilla.samba.org/show_bug.cgi?id=9634

Fix for https://bugzilla.samba.org/show_bug.cgi?id=9634

Add an option to smb.conf to list authorized zone transfer clients.
Implement restriction in dlz_bind9 module to allow transfers only to selected IPs.
Deny zone transfer by default in dlz_bind9.

Adds test for the restriction in DNZ zone transfer clients.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=9634

Signed-off-by: Julien ROPÉ <jrope@linagora.com>
Reviewed-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
Autobuild-User(master): Jeremy Allison <jra@samba.org>
Autobuild-Date(master): Fri Jun 11 19:28:10 UTC 2021 on sn-devel-184