WebUI: Hide incorrectly shown buttons on hosts tab in ID Views
    
    There was missing default value for evaluator adapter.
    In that case the adapter variable could be undefined and
    it crashes on building adapter. Therefore it did not
    evaluate all evaluators. That is the reason why 'Delete'
    and 'Add' buttons were incorrectly shown.
    Default value is now set to empty object.
    
    https://fedorahosted.org/freeipa/ticket/6546
    
    Reviewed-By: Petr Vobornik <pvoborni@redhat.com>