r13211: Fix remote password changing if password must change is set

r13211: Fix remote password changing if password must change is set

The problem was that the ntlmssp bind silently failed in that case, we have to
do it anonymously. Or does anybody have a better idea?

Give a better error message if something else is wrong with the account.

Volker
(This used to be commit 0e24c701ce3755d71de7fdccb9f4564b381bf996)