title: Prestashop api - creating order history doesn't send e-mail
body: <p>I'm trying to add order history (and change order_state with that) by using prestashop api:</p>
  
  <pre><code>$xml = $this-&gt;api-&gt;get(array('url' =&gt; $url . '/api/order_histories?schema=blank'));
  $xml-&gt;order_history-&gt;id_order_state = 4;
  $xml-&gt;order_history-&gt;id_order = $order_id;
  unset( $xml-&gt;order_history-&gt;id );
  unset( $xml-&gt;order_history-&gt;date_add );
  $xml = $this-&gt;api-&gt;add(array(
    'resource' =&gt; 'order_histories',
    'postXml' =&gt; $xml-&gt;asXML()
  ));
  </code></pre>
  
  <p>It works just fine (order_state is changed) but presta doesn't sending any notification to buyer.</p>