Remove bad link.

doc/xdocs/reference.xml

@@ -33,16 +33,6 @@
         <table>
           <tr><th>Document</th><th>Description</th></tr>
 
-          <tr>
-            <td>
-              <a href="docbook/index.html">Reference Guide HTML</a>
-            </td>
-            <td>
-              This is a good place to start if you want
-              to use the Acegi Security System to secure your applications.
-            </td>
-          </tr>
-
           <tr>
             <td>
               <a href="docbook/acegi.html">Reference Guide HTML Single Page</a>