Package `License` field and `LICENSE` file disagree

[fingolfin]

Your PackageInfo.g file says:

License := "GPL-3.0-or-later",

and your LICENSE file also says "either version 3 of the License, or
(at your option) any later version"

But then it goes on to say "either version 2 of the License" and finally it contains version 2 of the GPL!

Either change the former to places say "version 2 or later" (that would match what GAP does), or else replace the GPL 2 license text by GPL 3.