Fix "patchwork website" broken link, replace with github repo

Author: Dragorn421

patchwork/templates/patchwork/about.html

@@ -8,7 +8,7 @@
   <h1>About Patchwork</h1>
 
   <p>Patchwork is free software, and is available from the <a
-     href="http://jk.ozlabs.org/projects/patchwork/">Patchwork website</a>.
+     href="https://github.com/getpatchwork/patchwork">Patchwork repository</a>.
      Documentation is available on <a
      href="http://patchwork.readthedocs.io/">Read the Docs</a>.</p>