hide deferred accounts from thunderbird folder pane, sr=mscott 30057

mail/base/content/messenger.xul

@@ -171,6 +171,7 @@
             <conditions>
               <content uri="?container"/> 
               <member container="?container" child="?member" />
+              <triple subject="?member" predicate="http://home.netscape.com/NC-rdf#IsDeferred" object="false"/>
             </conditions>
 
             <bindings>