Relicense from GPLv3 to GPLv3+.

LICENSE.md

@@ -1,3 +1,5 @@
-All **source code** in `src/`is copyright © 2019 Andrew Belt and Befaco contributers and is licensed under the [GNU General Public License v3.0](LICENSE-GPLv3.txt).
+All **source code** is copyright © 2019-2020 Andrew Belt and Befaco contributers.
+
+This program is free software: you can redistribute it and/or modify it under the terms of the [GNU General Public License](https://www.gnu.org/licenses/gpl-3.0.en.html) as published by the [Free Software Foundation](https://www.fsf.org/), either version 3 of the License, or (at your option) any later version.
 
 The **panel graphics** in the `res/` directory are copyright © Befaco and are used and distributed with permission.

plugin.json

@@ -1,7 +1,7 @@
 {
   "slug": "Befaco",
   "version": "1.0.1",
-  "license": "GPL-3.0-only",
+  "license": "GPL-3.0-or-later",
   "name": "Befaco",
   "author": "VCV",
   "authorEmail": "contact@vcvrack.com",