It is supposed to refer to the property of the file on disk (if there is
any).

Task-number: QTCREATORBUG-4998
Change-Id: Iaed62c17d124b364aecec4d1f910046bade42d40
Reviewed-by: Tobias Hunger <tobias.hunger@nokia.com>
Reviewed-by: Daniel Teske <daniel.teske@nokia.com>
Reviewed-by: Eike Ziller <eike.ziller@nokia.com>