*: re-license under GNU GPL v3

Signed-off-by: Maciej Barć <xgqt@protonmail.com>

src/maintainers

@@ -2,9 +2,24 @@
 
 
 """
-Original author: XGQT
-Licensed under the ISC License
+This file is part of scripts.
+
+scripts 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
+(at your option) any later version.
+
+scripts is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with scripts.  If not, see <https://www.gnu.org/licenses/>.
+
+Original author: Maciej Barć (xgqt@protonmail.com)
 Copyright (c) 2020, src_prepare group
+Licensed under the GNU GPL v3 License
 
 How to use:
  - cd into the repository root: