Remove legacy security documentation page

Author: ujibang

_includes/docs-sidebar.html

@@ -26,7 +26,6 @@ <h2 class="mt-2">RESTHeart Cloud <span class="text-small text-white">Coming soon
     <li><a href="/docs/cloud/root-user-setup">Root user setup</a></li>
     <li><a href="/docs/cloud/examples">Examples & Use Cases</a></li>
     <li><a href="/docs/cloud/user-management">User Management</a></li>
-    <li><a href="/docs/cloud/security">Security</a></li>
 </ul>
 
 <a data-toggle="collapse" href="#setup" role="button" aria-expanded="false" aria-controls="collapseExample">