[WIP] converter: only enable tar-rafs conversion by env NYDUS_ENABLE_TAR2RAFS#635

imeoer wants to merge 1 commit intocontainerd:maincontainerd/nydus-snapshotter:mainfrom

imeoer:disable-tar-rafsimeoer/nydus-snapshotter:disable-tar-rafsCopy head branch name to clipboard