segment: use mpegts_flags instead of the deprecated resend_headers option

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/segment.c

@@ -222,7 +222,7 @@ static int segment_start(AVFormatContext *s, int write_header)
     }
 
     if (oc->oformat->priv_class && oc->priv_data)
-        av_opt_set(oc->priv_data, "resend_headers", "1", 0); /* mpegts specific */
+        av_opt_set(oc->priv_data, "mpegts_flags", "+resend_headers", 0);
 
     if (write_header) {
         if ((err = avformat_write_header(oc, NULL)) < 0)