fix error

app/controllers/admin/asks_controller.rb

@@ -277,7 +277,7 @@ class Admin::AsksController < OrbitAdminController
       ask_setting = AskSetting.create() if ask_setting.nil?
     end
     ask_setting.custom_fields.select{|k,v| v['type']=='file' || v['type']=='image'}.each do |k,v|
-      file = temp_params['custom_values'][k]
+      file = temp_params['custom_values'][k] rescue nil
       if !file.blank?
         if v['type']=='image'
           all_to_save += [[k,AskImage.new(file: file,ask_question_id: @ask_question.id)]]