fix footer bug tracking link

Author: Tim Watson

_includes/footer.html

@@ -22,7 +22,7 @@
         <ul class="footer-links">
           <li><a href="http://github.com/haskell-distributed/">Source</a></li>
           <li class="muted">&middot;</li>
-          <li><a href="https://github.com/haskell-distributed/distributed-process/issues?state=open">Issues</a></li>
+          <li><a href="https://cloud-haskell.atlassian.net">Issues</a></li>
           <li class="muted">&middot;</li>
           <li><a href="/wiki.html">Wiki</a></li>
           <li class="muted">&middot;</li>