QtIFW

Fix compile for gcc 4.7.3

error: looser throw specifier for 'virtual VerbosePrinterCallback::~VerbosePrinterCallback()'

Change-Id: Id0dc7761eb011e8c39f6bda8257f636cbd3a1cf7
Reviewed-by: Kai Koehne <kai.koehne@theqtcompany.com>