update SessionRestrictionByIP with security warning

diff --git a/en/manual.xml b/en/manual.xml
index 6603f52..a61bd2c 100644 (file)
--- a/en/manual.xml
+++ b/en/manual.xml
@@ -867,6 +867,11 @@ budget_code: 922$a</programlisting></para>
                     happens.</para>
                 </listitem>
               </itemizedlist></para>
+            <important>
+              <para>This is meant to help those whose IP address changes several times during the
+                day, setting this preference to 'Disable' is not recommended otherwise because it is
+                removing important security features from your staff client.</para>
+            </important>
           </section>
 
           <section id="SessionStorage">