Fixed wrong price value of GroupOrder when finishing an order.

app/models/order.rb

@@ -170,6 +170,9 @@ class Order < ActiveRecord::Base
           oa.update_attribute(:article_price, oa.article.article_prices.first)
           oa.group_order_articles.each { |goa| goa.save_results! }
         end
+        # Update GroupOrder prices
+        group_orders.each { |go| go.update_price! }
+        
         # set new order state (needed by notify_order_finished)
         update_attributes(:state => 'finished', :ends => Time.now, :updated_by => user)