Double-pendulum-model-in-Cpp.md

@@ -8,7 +8,7 @@
   </tr>
   <tr>
     <th colspan="2">Browse <a href="https://gitlab.onelab.info/doc/tutorials/tree/master/PendulumC++/">model files</a>
-    &mdash; Download <a href="http://onelab.info/files/PendulumC++.zip">zip archive</a></th>
+    &mdash; Download <a href="https://onelab.info/files/PendulumC++.zip">zip archive</a></th>
   </tr>
 </table>