wwviaudio: fix license in _info, symlink (LGPL -> GPL)

Comments in code indicate this is actually GPL version 2 or later.

ccan/wwviaudio/LICENSE

@@ -1 +1 @@
-../../licenses/LGPL-2.1
+../../licenses/GPL-2

ccan/wwviaudio/_info

@@ -37,7 +37,7 @@
  *      wwviaudio_cancel_all_sounds();
  *      wwviaduio_stop_portaudio();
  *
- * License: LGPL (v2.1 or any later version)
+ * License: GPL (v2 or any later version)
  *
  */
 int main(int argc, char *argv[])