deliver app config. fix wrong value cause error for default widget

app/helpers/admin/page_parts_helper.rb

@@ -25,8 +25,15 @@ module Admin::PagePartsHelper
     local_item = @part if local_item.nil? && @part
     local_item = @page if local_item.nil? && @page
     res = ''
-    choosen_value = prefill_value || local_item[:widget_field][i][0]
-    choosen_field_is_link = (@module_app.widget_fields.select{|t| t[0].to_s==choosen_value}.first)[2]==:link
+
+    choosen_value = prefill_value || (local_item[:widget_field][i][0] rescue nil)
+
+    if choosen_value
+      choosen_field_is_link = (@module_app.widget_fields.select{|t| t[0].to_s==choosen_value}.first)[2]==:link
+    else
+      choosen_field_is_link = false
+    end 
+    
 
     if choosen_field_is_link
       value = case local_item