Updated security manual

documentation/security.html

@@ -26,13 +26,11 @@
 
 <p>We recommend you don't take security issues too lightly. Chamilo is security-audited at least once a year, but you're never too sure. This list is a work in progress. Feel free to recommend additional measures by sending us an e-mail at info@chamilo.org.</p>
 
-
 <h2><b>Contents</b></h2>
-
 <ol>
-
   <li><a href="#1.Disclosing-server-info">Disclosing server info</a></li>
   <li><a href="#2.Keeping-up-to-date">Keeping up to date</a></li>
+  <li><a href="#3.Using-safe-browsers">Using safe browsers</a></li>
 </ol>
 
 <h2><a name="1.Disclosing-server-info"></a>Disclosing server info</h2>