MINOR: mux-h1/mux-fcgi: Don't set TUNNEL mode if payload length is unknown

Responses with no C-L and T-E headers are no longer switched in TUNNEL mode
and remains in DATA mode instead. The H1 and FCGI muxes are updated
accordingly. This change reflects the real message state. It is not a true
tunnel. Data received are still part of the message.

It is not a bug. However, this message may be backported after some
observation period (at least as far as 2.2).
3 files changed