Windows: kauth search for kerberos iv port first

Windows: kauth search for kerberos iv port first

Modify src/kauth/user_nt.c to match the service name search
order of the Unix code:

 kerberos4
 kerberos-iv
 kerberos

The standard Windows SERVICES file includes "kerberos-iv" as
port 750.

FIXES 127907

Reviewed-on: http://gerrit.openafs.org/6430
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Tested-by: Jeffrey Altman <jaltman@secure-endpoints.com>
Reviewed-by: Jeffrey Altman <jaltman@secure-endpoints.com>
(cherry picked from commit 2cdd59d8f318193d0ef7937910466531caf1c963)

Change-Id: I936c35bbd45395f26ad6c523b72398584d1384f9
Reviewed-on: http://gerrit.openafs.org/6819
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementix.org>