Issue title: setUsername() on userbots not working
 Issue body: throws an error about email field required
 Comments: 
 Comment 0: According to #697 , is fixed in fbcea236c53ab19bb74928933d0d144141403312 and available on indev.
 Comment 1: changed from the email field required to 'Password does not match', having used login with token
 Comment 2: Ok, as of https://github.com/hydrabolt/discord.js/commit/9308d2ead31edb12651fc1c2840945bcbf9fbdfe this is fixed, but you will still have to set the password when logging in with a token:
```js
client.login('token');
client.password = 'account password';
// ready to change username
```

Unfortunately, there's no way around this for user accounts and a password still has to be provided (which does make tokens a bit redundant for user accounts).
 Comment 3: Still not working for me. Getting this error:
`message: 'Invalid Form Body\npassword: Password does not match.',
 code: 50035`
{'source': 'GithubIssues', 'repo_name_with_owner': 'hydrabolt/discord.js', 'issue_id': 176764154, 'repo_stars': 2121.0}