Prefer TCP connections to UDP in krb5 clients
    
    In general, TCP is a better fit for FreeIPA due to large packet sizes.
    
    However, there is also a specific need for TCP when using OTP. If a UDP
    packet is delivered to the server and the server takes longer to process
    it than the client timeout (likely), the OTP value will be resent.
    Unfortunately, this will cause failures or even lockouts. Switching to
    TCP avoids this problem altogether.
    
    https://fedorahosted.org/freeipa/ticket/4725
    
    Reviewed-By: Martin Kosek <mkosek@redhat.com>