use https for apachecon banner
diff --git a/content/_layouts/default.html b/content/_layouts/default.html
index bae5a1b..982ea34 100644
--- a/content/_layouts/default.html
+++ b/content/_layouts/default.html
@@ -134,9 +134,9 @@
<li><a href="https://www.apache.org/foundation/thanks.html">ASF Sponsors</a></li>
<li><a href="https://www.apache.org/security/">Security</a></li>
</ul>
- <iframe src="http://www.apache.org/ads/buttonbar.html"
- style="border-width:0; float: left" frameborder="0" scrolling="no"
- width="135" height="265"></iframe>
+ <iframe src="https://www.apache.org/ads/buttonbar.html"
+ style="border-width:0; float: left" frameborder="0" scrolling="no"
+ width="135" height="265"></iframe>
</div>
<div class="col-xs-12 col-sm-9">
{{ content }}
