Produces a patched haproxy using nix for consuption as an oci layer.
This patch was submitted to the haproxy mailing list here: www.mail-archive.com/haproxy@formilux.org/msg44503.html mirroring the following commit: https://github.com/jrobsonchase/haproxy/commit/0f040d79ef61b1a3ccf59f4fc123678fcf5c6e32