I have /api/v1/updates behind envoy, I noticed that this endpoint was causing some issues and it turns out that it's returning a content-length header on this HTTP 204.

To reproduce

curl --http2-prior-knowledge -H "Cookie: defguard_session=MYCOOKIE;" http://localhost:8000/api/v1/updates -v

And you'll see something like:

* Request completely sent off
< HTTP/2 204 
< content-type: application/json
< x-defguard-version: 1.5.0-a29ac10
* Invalid HTTP header field was received: frame type: 1, stream: 1, name: [content-length], value: [34]
* HTTP/2 stream 1 was not closed cleanly: PROTOCOL_ERROR (err 1)
* Connection #0 to host localhost left intact
curl: (92) Invalid HTTP header field was received: frame type: 1, stream: 1, name: [content-length], value: [34]

A 204 should be empty