sttrb / loggingrb: Use GPLv2+ as license, not AGPLv3+
according to Holger, using AGPLv3+ at the time was a mistake and the
license should always have indicated GPLv2+.
diff --git a/include/osmocom/core/strrb.h b/include/osmocom/core/strrb.h
index c563d1b..7507cf4 100644
--- a/include/osmocom/core/strrb.h
+++ b/include/osmocom/core/strrb.h
@@ -5,7 +5,7 @@
*
* This program is free software; 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
+ * the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,