typo in link to versions.html (#3408)

Reviewed By: NicolasHug

Differential Revision: D26605311

fbshipit-source-id: 10dd9a0456dfbe2dc2002a4e32d95422f5e155a5

Author: fmassa

docs/source/_templates/layout.html

@@ -2,7 +2,7 @@
 
 {% block sidebartitle %}
     <div class="version">
-      <a href='http://pytorch.org/docs/vision/versions.html'>{{ version }} &#x25BC</a>
+      <a href='https://pytorch.org/vision/versions.html'>{{ version }} &#x25BC</a>
     </div>
     {% include "searchbox.html" %}
 {% endblock %}