Minecraft.net skin downloader doesn't accept chunked encoding

When using the https://minecraft.net/profile/skin/remote?url=<image url> service, the client on the backend that downloads the skin claims to support HTTP 1.1 but fails to accept responses that are using chunked encoding. This has caused me a lot of grief trying to get my server to stop sending it; the only solution I've found on my end is hacky and unsustainable.