Licensecheck returns UNKOWN, but it's GPL

[Luca Niccoli <lultimouomo@gmail.com>]

Souce files of the program I'm packaging contain the following header:

/* fswebcam - Small and simple webcam for *nix               */
/*===========================================================*/
/* Copyright (C)2005-2006 Philip Heron <phil@firestorm.cx>   */
/*                                                           */
/* This program is distributed under the terms of the GNU    */
/* General Public License, version 2. You may use, modify,   */
/* and redistribute it under the terms of this license. A    */
/* copy should be included with this source.                 */

which isn't recognised as a GPL license statement by licensecheck.
What should I do?
Simply ignore it, file a bug against licensecheck, file a bug against upstream?
The statements looks sound to me, so I would mind the last choice...
Thanks
Luca