DEVEL15-windows-nim-plugin-krb5-referrals-compat-20070209

DEVEL15-windows-nim-plugin-krb5-referrals-compat-20070209

MIT Kerberos version 5 release 1.6 adds support for referrals in the
client.  As a result krb5_get_host_realm() returns the nul-string for
the realm whenever there is no local domain-realm mapping in the
profile.

aklog must now manually perform the fallback to using the domain of
the vlserver as basis for the realm name if referrals fail.

This will be required for KFW 3.2 support.

(cherry picked from commit 584e1bd98eb4258a2cd1a517f7d49c71407983b5)