Add Git LFS 2.1.1 to prebuilt x86 image

Closed Stan Hu requested to merge sh-add-git-lfs-support into master

Git LFS v2.x has a post-checkout hook that verifies support for fetching LFS files. Without the git-lfs binary, fetches in CI builds could fail if the build cache has this hook installed.

There is no official ARM release build at the moment. See for more details.

Closes #2245 (closed)