Make sure we call stop before removing a page.

Fixes a spinning cursor in case the page was not fully
loaded and we where closing it at the same time.

Change-Id: Iae6efac70c0c8be2f84e6b1551275bbdf9c5aab3
Reviewed-by: Niels Weber <niels.2.weber@nokia.com>
Reviewed-by: Karsten Heimrich <karsten.heimrich@nokia.com>

src/plugins/help/helpviewer.h

@@ -100,6 +100,7 @@ public:
 public slots:
     void copy();
     void home();
+    void stop();
 
     void forward();
     void backward();