Use https for license link

Signed-off-by: Michal Čihař <michal@cihar.com>

Author: nijel

pmaweb/templates/license.html

@@ -64,7 +64,7 @@ <h2>Website Content</h2>
 
 <p>
 Website content is released under 
-<a href="http://creativecommons.org/licenses/by-sa/3.0/">Creative Commons
+<a href="https://creativecommons.org/licenses/by-sa/3.0/">Creative Commons
 Attribution-Share Alike 3.0 Unported</a>.
 </p>