Check normalization only for IDNA domains
    
    Backward compability with older IPA versions which allow to use uppper
    case. Only IDNA domains will be checked.
    
    https://fedorahosted.org/freeipa/ticket/4382
    
    Reviewed-By: Martin Kosek <mkosek@redhat.com>
    Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>