Windows: If SecurityLevel is configured use it for vos.exe and pts.exe

Windows: If SecurityLevel is configured use it for vos.exe and pts.exe

If the SecurityLevel registry value indicates that crypt should be
the default, then always set -encrypt for vos.exe and pts.exe.

Reviewed-on: http://gerrit.openafs.org/648
Reviewed-by: Jeffrey Altman <jaltman@openafs.org>
Tested-by: Jeffrey Altman <jaltman@openafs.org>