Fix GitHub link in FAQ (#1672)

Author: froque

src/site/fml/faq.fml

@@ -337,7 +337,7 @@
     <p>
       JUnit is hosted
       on <a
-      href="http://github/junit-team/junit4">GitHub</a>.
+      href="https://github.com/junit-team/junit4">GitHub</a>.
       Please use the tools provided by GitHub for your
       submissions.
     </p>