license: Add correct license file with GPLv3
Project is licensed under GNU GPLv3 license, however contained incorrect license file with the AGPL instead of GPLv3 license.
This MR adds file with correct version of license GPLv3.
Project is licensed under GNU GPLv3 license, however contained incorrect license file with the AGPL instead of GPLv3 license.
This MR adds file with correct version of license GPLv3.