Show "Follow link" context menu item for links without text

The standard context menu currently doesn't have the "Follow link" item for e.g.
the image links on https://www.qt.io

 .

Change-Id: I5b9d620135c7a8e65bd95a0ab07a76278e56cad0
Reviewed-by: Michal Klocek <michal.klocek@qt.io>