Make ipa-client-automount backwards compatible
    
    ipa-client-automount calls automountlocation-show command during the
    process. Unfortunately, FreeIPA commands are forward compatible only
    and thus fail the installer.
    
    Similarly to ipa-client-install, call XML-RPC interface directly
    with version fixed to 2.0 (command was already available at that
    version) to fix the failure.
    
    https://fedorahosted.org/freeipa/ticket/4290
    
    Reviewed-By: Rob Crittenden <rcritten@redhat.com>