s3-krb5 Fix Kerberos on FreeBSD with Samba4 DCs

s3-krb5 Fix Kerberos on FreeBSD with Samba4 DCs

The idea of this patch is: Don't support a mix of different kerberos
features.

Either we should prepare a GSSAPI (8003) checksum and mark the request as
such, or we should use the old behaviour (a normal kerberos checksum of 0 data).

Sending the GSSAPI checksum data, but without marking it as GSSAPI broke
Samba4, and seems well outside the expected behaviour, even if Windows accepts it.

Andrew Bartlett
(cherry picked from commit 3b4db34011f06fb785153fa9070fb1da9d8f5c78)

Signed-off-by: Stefan Metzmacher <metze@samba.org>
(cherry picked from commit b31c9cf18a5bd592912bd300e028d0798e93978d)