qt: fix fading edge effect not gone when hovered
When listView.itemAtIndex(0)
is used, the delegate item is
not resolved when new items added which makes it remain
null.
When listView.count
is referred as done here, the QML
engine establishes a relational binding and this causes
the property to be updated each time the count is updated.
Regression since 300b3b9c.
Request review @chub.