when write total.m3u8,don't write #EXT-X-DISCONTINUITY when the total.m3u8 is new created

@@ -878,7 +878,7 @@ int SrsHlsMuxer::segment_close(string log_desc)
 					erase_last_endlist = true;
 					m3u8_total_endlist_saved = false;
 				}
-				if (currentSeg->sequence_no != 0) {
+				if (this->total_duraion != 0) {
 					// #EXT-X-DISCONTINUITY\n
 					ss << "#EXT-X-DISCONTINUITY" << SRS_CONSTS_LF;
 					srs_verbose("write m3u8 segment discontinuity success.");