Stream alerts for YouTube no longer works: "Channel does not exist"

### What Red version are you using?

3.4.14

### Cog name

Streams

### Command name

streamalert youtube

### What did you expect to happen?

I'll now send a notification in this channel when ****** is live.

### What actually happened?

Error in command 'streamalert youtube'. Check your console or logs for details.

### How can we reproduce this error?

1.[prefix]streamalert youtube [channelid/name]
2.
3.
...

### Anything else?

Was working properly before the 3.4.14 update.
Have tried restarting bot. Have not tried restarting device hosting the bot.
Tried reassigning the API Key.

Twitch variant is working as intended

Below is the error log in the console.
```py
[14:18:14] ERROR [red] Exception in command 'streamalert youtube'

│ C:\Users\***\redenv\lib\site-packages\discord\ext\commands\core.py:85 in wrapped │
│ > 85 ret = await coro(*args, **kwargs) │
│ C:\Users\***\redenv\lib\site-packages\redbot\cogs\streams\streams.py:322 in youtube_alert │
│ > 322 await self.stream_alert(ctx, YoutubeStream, channel_name_or_id) │
│ C:\Users\***\redenv\lib\site-packages\redbot\cogs\streams\streams.py:414 in stream_alert │
│ > 414 exists = await self.check_exists(stream) │
│ C:\Users\***\redenv\lib\site-packages\redbot\cogs\streams\streams.py:701 in check_exists │
│ > 701 await stream.is_online() │
│ C:\Users\***\redenv\lib\site-packages\redbot\cogs\streams\streamtypes.py:145 in is_online │
│ > 145 for video_id in get_video_ids_from_feed(rssdata): │
│ C:\Users\***\redenv\lib\site-packages\redbot\cogs\streams\streamtypes.py:49 in get_video_ids_from_feed │
│ > 49 root = ET.fromstring(feed) │
│ C:\Python38\lib\xml\etree\ElementTree.py:1320 in XML │
│ > 1320 parser.feed(text)
ParseError: not well-formed (invalid token): line 2, column 11
```