In user to user mode the requested name is something like TERMSRV/<host>@<realm>,
but we can request a TGT only for <host>$@<realm> as it's the only account that
we have in our keytab that can do it. So this patch fix the research in the keytab, and
retrieves the TGT using <host>$@<realm> instead of TERMSRV/<host>@<realm>. That
fixes NLA server-side with kerberos users2user.