Use Anonymous user to obtain FAST armor ccache
    
    The anonymous user allows the framework to obtain an armor ccache without
    relying on usable credentials, either via a keytab or a pkinit and
    public certificates. This will be needed once the HTTP keytab is moved away
    for privilege separation.
    
    https://fedorahosted.org/freeipa/ticket/5959
    
    Signed-off-by: Simo Sorce <simo@redhat.com>
    Reviewed-By: Jan Cholasta <jcholast@redhat.com>