libads: Keep 'good' server at the head of custom KDC list
When creating a custom krb.conf file for a domain, make sure
that the DC which already answered the ldap ping is not queried
again, and is always first in the custom KDC list. This has two
advantages:
1. Avoid re-sending an ldap ping to this server
2. The generated list is made up of the servers that answered
first. Since the DC which already answered an LDAP ping
is typically the "last good server", this change keeps it
out of the contest and guarantees that we keep using last
good server as long as it works.
Signed-off-by: Uri Simchoni <urisimchoni@gmail.com>
Reviewed-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Alexander Bokovoy <ab@samba.org>