Write sequence header at each key frame / fwd key frame

Change-Id: I4447508efd711fa9f0b92a83a43c18b0ad7cb69f
diff --git a/av1/encoder/bitstream.c b/av1/encoder/bitstream.c
index e64aee8..2ce6057 100644
--- a/av1/encoder/bitstream.c
+++ b/av1/encoder/bitstream.c
@@ -4155,7 +4155,7 @@
   // write sequence header obu at each key frame or intra_only frame,
   // preceded by 4-byte size
   if (cm->current_frame.frame_type == INTRA_ONLY_FRAME ||
-      cpi->ppi->gf_group.refbuf_state[cpi->gf_frame_index] == REFBUF_RESET) {
+      cm->current_frame.frame_type == KEY_FRAME) {
     obu_header_size = av1_write_obu_header(
         level_params, &cpi->frame_header_count, OBU_SEQUENCE_HEADER, 0, data);
     obu_payload_size =