Symbian: QMenu misbehaves if first item of a very long context menu is selected

If there is a very long context list in QMenu and user selects the first item of the list,
QMenu still enables "up scrolling" for it, making the menu items to disappear from screen if scrolling is done upwards.

This relates to QMenu::popup where it automatically adds "up scroller" without actually checking if the selected item
can be scrolled upwards.