MINOR: mux-h2: Remove useless test on ES flag in h2_frt_transfer_data()

Same test is already performed in the caller function, h2c_frt_handle_data().

This patch should be backported to 1.9.
diff --git a/src/mux_h2.c b/src/mux_h2.c
index d91cd08..c31bf8d 100644
--- a/src/mux_h2.c
+++ b/src/mux_h2.c
@@ -3765,12 +3765,6 @@
 	h2c->rcvd_s += h2c->dpl;
 	h2c->dpl = 0;
 	h2c->st0 = H2_CS_FRAME_A; // send the corresponding window update
-
-	if (h2c->dff & H2_F_DATA_END_STREAM) {
-		h2s->flags |= H2_SF_ES_RCVD;
-		if (h2s->cs)
-			h2s->cs->flags |= CS_FL_REOS;
-	}
 	if (htx)
 		htx_to_buf(htx, csbuf);
 	return 1;