The patch was pushed in HAProxy 1.7 few days ago: http://git.haproxy.org/?p=haproxy-1.7.git;a=commit;h=6917b734023c0de06da2e1c2e31ff63d0358764b
Waiting the next 1.7 release (1.7.11), you can clone the repository or use the right snapshot:
- Latest 1.7 snapshot: http://www.haproxy.org/download/1.7/src/snapshot/haproxy-ss-LATEST.tar.gz
- The first snapshot including the patch: http://www.haproxy.org/download/1.7/src/snapshot/haproxy-ss-20180227.tar.gz