Fixed broken eager loading in orders#edit.

app/controllers/orders_controller.rb

@@ -82,7 +82,7 @@ class OrdersController < ApplicationController
   # Page to edit an exsiting order.
   # editing finished orders is done in FinanceController
   def edit
-    @order = Order.find(params[:id], :include => :articles)
+    @order = Order.includes(:articles).find(params[:id])
   end
 
   # Update an existing order.