MEDIUM: mux-h1: Don't expect data from server as long as request is unfinished

MEDIUM: mux-h1: Don't expect data from server as long as request is unfinished

On client side, as long as the request is unfinished, the H1 stream states
it does not expect data from the server. It does not mean the server must
not send its response but only it may wait to receive the whole request with
no risk to trigger a read timeout.

When the request is finished, the H1 stream reports it expects to receive
data from the opposite endpoint.

The purpose of this patch is to never report a server timeout on receive if
the client is still uploading data. This way, it is possible to have a
smaller server timeout than the client one.