🐛 User couldn't edit file sets

parent_doc is not a solr document, so calling ['has_model_ssim'] produced and error.

app/helpers/hyku_helper.rb

@@ -21,7 +21,7 @@ def admin_only_tenant_creation?
   end
 
   def parent_path(parent_doc)
-    model = parent_doc['has_model_ssim'].first
+    model = parent_doc.has_model.first
     path = "hyrax_#{model.underscore}_path"
     main_app.send(path, parent_doc.id)
   end