git version 2.4.0
Removing ffbuild/config.log
From https://git.ffmpeg.org/ffmpeg
 * branch            master     -> FETCH_HEAD
HEAD is now at a1801e0 avcodec/nvenc: add AV1 hierarchical B-frame reference mode support
a1801e06ae9bc6b3dbbc7087c14d6caa60e8d55b