Add print if no json data

backend/download/src/yt_dlp_handler.py

@@ -429,6 +429,7 @@ class DownloadPostProcess(DownloaderBase):
             channel = YoutubeChannel(channel_id)
             channel.get_from_es()
             if not channel.json_data:
+                print(f"{channel_id}: skip failed channel import")
                 continue
 
             overwrites = channel.get_overwrites()
@@ -463,6 +464,7 @@ class DownloadPostProcess(DownloaderBase):
             playlist = YoutubePlaylist(playlist_id)
             playlist.get_from_es()
             if not playlist.json_data:
+                print(f"{playlist_id}: skip failed playlist import")
                 continue
 
             playlist.add_vids_to_playlist()