s3/smbd: ensure global "smb encrypt = off" is effective for SMB 3.1.1 clients
If encryption is disabled globally, per definition we shouldn't allow
enabling encryption on individual shares.
The behaviour of setting
[Global]
smb encrypt = off
[share]
smb encrypt = required
must be to completely deny access to the share "share".
This was working correctly for clients when using SMB 3 dialects <
3.1.1, but not for 3.1.1 with a negprot encryption context.
Bug: https://bugzilla.samba.org/show_bug.cgi?id=12520
Signed-off-by: Ralph Boehme <slow@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
(cherry picked from commit
6ae63d42f5aacddf5b7b6dbdfbe620344989e4e5)