MINOR: stats/htx: Don't add "Connection: close" header anymore in stats responses

On the client side, as far as possible, we will try to keep connection
alive. So, in most of cases, this header will be removed. So it is better to not
add it at all. If finally the connection must be closed, the header will be
added by the mux h1.

No need to backport this patch.
1 file changed