MINOR: stream: Remove tests on the option 'http-use-htx' in stream_new()

All streams created for an HTTP proxy must now use the HTX internal
resprentation. So, it is no more necessary to test the flag PR_O2_USE_HTX. It
means a stream is an HTX stream if the frontend is an HTTP proxy or if the
frontend multiplexer, if any, set the flag MX_FL_HTX.
diff --git a/src/stream.c b/src/stream.c
index 60f62c3..caf16c1 100644
--- a/src/stream.c
+++ b/src/stream.c
@@ -246,8 +246,8 @@
 		if (cs->conn->mux->flags & MX_FL_HTX)
 			s->flags |= SF_HTX;
 	}
-	/* Set SF_HTX flag for HTX frontends. */
-	if (sess->fe->mode == PR_MODE_HTTP && sess->fe->options2 & PR_O2_USE_HTX)
+        /* Set SF_HTX flag for HTTP frontends. */
+	if (sess->fe->mode == PR_MODE_HTTP)
 		s->flags |= SF_HTX;
 
 	/* attach the incoming connection to the stream interface now. */