License issue

In [LICENSE](https://github.com/hookforge/sighook/blob/44008bb46cc98edf9d69b72c2f19fca4b78a31b2/LICENSE) file, the project is licensed with GPL 2.0 license, but the [README.md](https://github.com/hookforge/sighook/blob/44008bb46cc98edf9d69b72c2f19fca4b78a31b2/README.md) declares LGPL 2.1. I'd like to confirm what license is actually being used.

Thanks.