Fix video duration parser

src/parser.nim

@@ -128,7 +128,7 @@ proc parseVideo(js: JsonNode): Video =
     views: js{"ext", "mediaStats", "r", "ok", "viewCount"}.getStr,
     available: js{"ext_media_availability", "status"}.getStr == "available",
     title: js{"ext_alt_text"}.getStr,
-    durationMs: js{"duration_millis"}.getInt
+    durationMs: js{"video_info", "duration_millis"}.getInt
     # playbackType: mp4
   )