Strange old file. Fix the license anyway.

Author: lrineau

Nef_3/SNC_walker/SNC_walking.nw

@@ -601,9 +601,10 @@ o = o_next;
 // Copyright (c) 2003 Max-Planck-Institute Saarbruecken (Germany).
 // All rights reserved.
 //
-// This file is part of CGAL (www.cgal.org); you may redistribute it under
-// the terms of the Q Public License version 1.0.
-// See the file LICENSE.QPL distributed with CGAL.
+// This file is part of CGAL (www.cgal.org).
+// You can redistribute it and/or modify it under the terms of the GNU
+// General Public License as published by the Free Software Foundation,
+// either version 3 of the License, or (at your option) any later version.
 //
 // Licensees holding a valid commercial license may use this file in
 // accordance with the commercial license agreement provided with the software.