puffin_http clients can't get firsts frame if they are short

**Describe the bug**
When firsts frames are short, puffin_http client (example: puffin_viewer) can't get firsts frames.

**To Reproduce**
Steps to reproduce the behavior:
1. start puffin_viewer
2. start an app with puffin_http server with short frames (and numbered frames)
3. look-at frame in viewer, there isn't the first frame(s)

**Expected behavior**
I expect to be able to get first frame in puffin_viewer

**Device:**
- OS: Fedora
- Version 36

Reproduce the issue with puffin_viewer and an app using a puffin_http server that emits short, numbered frames. Start by tracing how the client requests and receives the first frames, then verify that the viewer can display every initial frame, including short ones.

Written by the indexing model from the issue text.