sshd(8) list restrict as a future-proof way to restrict feature
enabled in ssh. It is supported since OpenSSH 7.2, out since
2016-02-29.
OpenSSH will ignore unknown options (see sshauthopt_parse in
auth-options.c), so it should be safe to add the option and
no-user-rc.
Co-authored-by: zeripath <art27@cantab.net>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>
