[Fix #775] If champ type is a multiple drop down list then display it properly

app/models/champ.rb

@@ -64,6 +64,8 @@ class Champ < ActiveRecord::Base
       case type_champ
       when 'date'
         Date.parse(value).strftime('%d/%m/%Y')
+      when 'multiple_drop_down_list'
+        drop_down_list.selected_options_without_decorator(self).join(', ')
       else
         value.to_s
       end