The [Firefox Add-ons page](https://addons.mozilla.org/en-US/firefox/addon/docsafterdark/) mentions the [Mozilla Public License 2.0](https://www.mozilla.org/MPL/2.0/). However, here in the GitHub repository the [LICENSE file](https://github.com/waymondrang/docsafterdark/blob/470aa217fe537dc7b91dfb4721a67fd1c699dab4/LICENSE) contains the GPLv3. Is that difference intended or is it a bug?
The Firefox Add-ons page mentions the Mozilla Public License 2.0. However, here in the GitHub repository the LICENSE file contains the GPLv3. Is that difference intended or is it a bug?