Mp4: fixed seeking to a track end.

When "start" value is equal to a track duration the request
fails with "time is out mp4 stts" like it did before track
duration check was added.  Now such tracks are considered
short and skipped.

src/http/modules/ngx_http_mp4_module.c

diff --git a/src/http/modules/ngx_http_mp4_module.c b/src/http/modules/ngx_http_mp4_module.c
index c9b67ad..7a7ae6d 100644
--- a/src/http/modules/ngx_http_mp4_module.c
+++ b/src/http/modules/ngx_http_mp4_module.c
@@ -1507,7 +1507,7 @@
 
     start_time = (uint64_t) mp4->start * mp4->timescale / 1000;
 
-    if (duration < start_time) {
+    if (duration <= start_time) {
         ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
                        "tkhd duration is less than start time");
         return NGX_DECLINED;
@@ -1668,7 +1668,7 @@
 
     start_time = (uint64_t) mp4->start * timescale / 1000;
 
-    if (duration < start_time) {
+    if (duration <= start_time) {
         ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
                        "mdhd duration is less than start time");
         return NGX_DECLINED;