Better automatic translation update

gui/index.html

@@ -752,6 +752,7 @@
   <script src="angular-translate-loader.min.js"></script>
   <script src="jquery-2.0.3.min.js"></script>
   <script src="bootstrap/js/bootstrap.min.js"></script>
+  <script src="valid-langs.js"></script>
   <script src="app.js"></script>
 </body>
 </html>