changing description to value on tree

http://bugzilla.mozilla.org/show_bug.cgi?id=45198
r=hyatt

suite/common/pref/pref-applications.xul

@@ -72,7 +72,7 @@
               <treechildren flex="1">
                 <treeitem uri="?type">
                   <treerow>
-                    <treecell value="?description"/>
+                    <treecell value="?value"/>
                   </treerow>
                 </treeitem>
               </treechildren>