[Bug Report] Bot gives unknown error when trying to include youtube video with age restrictions

Nobody has claimed this yet.

### Bug Description

When you try to turn on a video with age restrictions on Youtube, the bot will give you an error IN THE TERMINAL, however the user sees that the bot has started playing music

### Steps to Reproduce

1. Play Youtube video with age restrictions (eg. `https://www.youtube.com/watch?v=1WiAo4-zMnA`)
2. Look into terminal
3. ~~Enjoy~~ See the error

### Expected Result

I expected the bot to write that there was an error, or in a better scenario, that it would play music

### Debug Output

```shell
System Properties:
java.version = 16.0.2
java.vm.name = Java HotSpot(TM) 64-Bit Server VM
java.vm.specification.version = 16
java.runtime.name = Java(TM) SE Runtime Environment
java.runtime.version = 16.0.2+7-67
java.specification.version = 16
os.arch = amd64
os.name = Linux

JMusicBot Information:
Version = 0.3.6
Owner = 338075554937044994
Prefix = h.
AltPrefix = null
MaxSeconds = 0
NPImages = false
SongInStatus = false
StayInChannel = true
UseEval = false
UpdateAlerts = true

Dependency Information:
JDA Version = 4.3.0_324
JDA-Utilities Version = 3.0.5
Lavaplayer Version = 1.3.78

Runtime Information:
Total Memory = 71
Used Memory = 35

Discord Information:
ID = 907398434594652220
Guilds = 1
Users = 2
```

### Additional Info

Here you can find the log file
http://haste.6vz.pw/gokemoviho.less

### Checklist

- [X] I have looked for information about this [within the documentation](https://jmusicbot.com/)
- [X] I have searched for similar issues [on the issues page](https://github.com/jagrosh/MusicBot/issues?q=is%3Aissue)
- [X] I am running the latest version of the bot: 

Start by reproducing the issue with the age-restricted YouTube URL and inspect the terminal output and linked log. Trace the playback request through the bot and its YouTube playback dependency; done means the failure is handled consistently and the user-visible playback state matches the actual result.

Written by the indexing model from the issue text.