CVE-2016-2112: selftest: servers with explicit "ldap server require strong auth"...

CVE-2016-2112: selftest: servers with explicit "ldap server require strong auth" options

The default is "ldap server require strong auth = yes",
ad_dc_ntvfs uses "ldap server require strong auth = allow_sasl_over_tls",
fl2008r2dc uses "ldap server require strong auth = no".

BUG: https://bugzilla.samba.org/show_bug.cgi?id=11644

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Günther Deschner <gd@samba.org>
Reviewed-by: Alexander Bokovoy <ab@samba.org>