MINOR: http_fetch/htx: Use stream flags instead of px mode in smp_prefetch_htx

In the function smp_prefetch_htx(), we must know if data in the channel's buffer
are structured or not. Before the proxy mode was tested. Now we test if the
stream is an HTX stream or not. If yes, we know the HTX is used to structure
data in the channel's buffer.
1 file changed