FileInProjectFinder: Try to find path in list of files even if project directory is empty

Change-Id: I4c7e783b7fc43fc3ff68a04fcb2ff3b2cf14e109
Reviewed-on: http://codereview.qt.nokia.com/310


Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Christiaan Janssen <christiaan.janssen@nokia.com>