avformat/utils: estimate_timings_from_pts - increase retry counter, fixes invalid duration for ts files with hevc codec

Fixes a mpegts file with hevc that fails estimating duration. Increasing number of
retries fixes the issue.

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 2d8c2f1a28)

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavformat/utils.c

@@ -2451,7 +2451,7 @@ static void estimate_timings_from_bit_rate(AVFormatContext *ic)
 }
 
 #define DURATION_MAX_READ_SIZE 250000LL
-#define DURATION_MAX_RETRY 4
+#define DURATION_MAX_RETRY 6
 
 /* only usable for MPEG-PS streams */
 static void estimate_timings_from_pts(AVFormatContext *ic, int64_t old_offset)