title: Prestashop 1.7 add new column to orders table
body: <p>Good day all.
  I'm doing a little module that should display a new column into the order table in backend.</p>
  
  <p>I've done this:</p>
  
  <p>in my module, I've done a new file into <code>my_module/controllers/admin/AdminOrderController.php</code></p>
  
  <p>in that file, I've written:</p>
  
  <pre><code>class AdminOrdersController extends AdminOrdersControllerCore
  {
  
      public function __construct()
      {
   print_r("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"); 
      }
  }
  </code></pre>
  
  <p>but once I go to the order list...nothing happens.
  (I've deleted the calls_index.php from var/cache/).
  what I'm doing wrong?
  Can you help me understand what I hae to do in order to add a new column to that table?</p>