tweak vod settings for varying iframe intervals

docker/rootfs/usr/local/nginx/conf/nginx.conf

@@ -52,6 +52,8 @@ http {
         vod_mode mapped;
         vod_max_mapping_response_size 1m;
         vod_upstream_location /api;
+        vod_align_segments_to_key_frames on;
+        vod_manifest_segment_durations_mode accurate;
 
         # vod caches
         vod_metadata_cache metadata_cache 512m;