Upload Header Response

I am trying to update replay sever from Epic Github, so it works with current version of httpStreamers.

All is going well except I cant figure out proper response to Upload Header request.
After saving Upload Header (which works and I save all 88 bytes onto a server), I get this on client

[2018.01.22-23.57.02:325][  6]LogHttpReplay: Error: FHttpNetworkReplayStreamer::HttpHeaderUploadFinished. FAILED, Response code: 200, Extra info: URL: http://localhost:8083/replay/5ecba0fd-250b-4dba-9fde-5817af334eb0/file/replay.header?numChunks=0&time=89, Verb: POST, Content-Type: application/octet-stream, User-Agent: game=SpectateGitFix, engine=UE4, version=4.18.3-0+++UE4+Release-4.18, platform=Windows, osver=6.2.9200.1.256.64bit, Content-Length: 88, Pragma: no-cache, Expect:

I tracked it down to HttpNetworkReplayStreaming.cpp line 555, but after that it is a black box for me. As you can see I am sending code 200 back, which seems logical to me. Any idea what to send back?

Expects a No Content (204) response code, it should be in the documentation tho, i had to dig it out of the engine source code.