We are not going to use gitter any more

Signed-off-by: Artem Sidorenko <artem@posteo.de>

Author: artem-sidorenko

themes/devsec/layouts/partials/footer.html

@@ -2,7 +2,6 @@
   <li><a href="/legal">Legal notice</a></li>
   <li><a href="/contributing">Contributing</a></li>
   <li><a href="https://twitter.com/devsecio">Twitter</a></li>
-  <li><a href="https://gitter.im/dev-sec/general?source=orgpage">Gitter</a></li>
   <li><a href="https://galaxy.ansible.com/dev-sec/">Ansible Galaxy</a></li>
   <li><a href="https://supermarket.getchef.com/cookbooks?q=hardening">Chef Community</a></li>
   <li><a href="https://forge.puppetlabs.com/hardening">Puppet Forge</a></li>