GNUTLS license information is incorrect

The license field of the GNUTLS' APKBUILD states the license is GPL-3.0-or-later while the real license according to the project itself is LGPL-2.1-or-later.

While this problem may sound trivial as doesn't stop anyone from using the package... but not under corporate conditions. We use Alpine Linux as base OS for our microcontainers, but we're not allowed to use any software on GPLv3 license. The apk list -i command is used in each container to validate that.

FYI: @ncopa