remove a tab

mail/base/content/msgMail3PaneWindow.js

@@ -1285,7 +1285,7 @@ function ClearMessagePane()
     // hide the message header view AND the message pane...
     HideMessageHeaderPane();
     gMessageNotificationBar.clearMsgNotifications();
-	ClearPendingReadTimer();
+    ClearPendingReadTimer();
   }
 }