[youtube_live_chat] fix bug when trying to set cookies

Closes #194

yt_dlp/downloader/youtube_live_chat.py

@@ -79,8 +79,7 @@ class YoutubeLiveChatReplayFD(FragmentFD):
 
         self._prepare_and_start_frag_download(ctx)
 
-        success, raw_fragment = dl_fragment(
-            'https://www.youtube.com/watch?v={}'.format(video_id))
+        success, raw_fragment = dl_fragment(info_dict['url'])
         if not success:
             return False
         try:

yt_dlp/extractor/youtube.py

@@ -2150,6 +2150,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
                 # This will error if there is no livechat
                 initial_data['contents']['twoColumnWatchNextResults']['conversationBar']['liveChatRenderer']['continuations'][0]['reloadContinuationData']['continuation']
                 info['subtitles']['live_chat'] = [{
+                    'url': 'https://www.youtube.com/watch?v=%s' % video_id, # url is needed to set cookies
                     'video_id': video_id,
                     'ext': 'json',
                     'protocol': 'youtube_live_chat_replay',