Remove obsolete link.

templates/pages/about/users.html

@@ -121,7 +121,7 @@ <h2>Technology</h2>
 </ul>
 <h2>Telecom</h2>
 <ul>
-	<li>Cisco (<a href="http://www.cisco.com/en/US/products/sw/voicesw/ps4371/products_user_guide_chapter09186a00800c252c.html">documentation</a>)</li>
+	<li>Cisco</li>
 	<li>Juniper Networks (<a href="http://www.juniper.net/techpubs/en_US/nsm2009.1/topics/task/verify/firewall-profiler-database-querying-nsm.html">documentation</a>)</li>
 	<li>NTT Data</li>
 	<li>Optus</li>