Login should remove whitespaces from username

[tubbadu]

• Did you check to see if this issue already exists?
• Is this only a single bug? Do not put multiple bugs in one issue.
• Is this a question or discussion? Don't use this, use https://lemmy.ml/c/lemmy_support .
• Is this a UI / front end issue? Use the lemmy-ui repo.

Issue Summary

trying to log in with username (with a whitespace at the end) results in an infinite loading. In my case it was caused by an error in bitwarden saved username, that added a whitespace, and took my a while to understand

Steps to Reproduce

1. click login
2. type your username followed by a whitespace, and your password
3. enjoy

it should only throw a trim() on the username before logging in I guess