BUG/MEDIUM: mux-h1: Always set CS_FL_EOI for response in MSG_DONE state

BUG/MEDIUM: mux-h1: Always set CS_FL_EOI for response in MSG_DONE state

During the message parsing, if in MSG_DONE state, the CS_FL_EOI flag must
always be set on the conn-stream if following conditions are met :

  * It is a response or
  * It is a request but not a protocol upgrade nor a CONNECT.

For now, there is no test on the message type (request or response). Thus
the CS_FL_EOI flag is not set for a response with a "Connection: upgrade"
header but not a 101 response.

This bug was introduced by the commit 3e1748bbf ("BUG/MINOR: mux-h1: Don't
set CS_FL_EOI too early for protocol upgrade requests"). It was backported
as far as 2.0. Thus, this patch must also be backported as far as 2.0.