typo in link to versions.html (#3408)

Author: mattip

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 %}