Users are able to register an account with the same username and email but with different letter cases

[alexlo510]

Summary

Users are able to register an account with the same username and email but with different letter cases.

Steps to reproduce

1. Click on the register button
2. Create an account and remember the username and email used for creating that account.
3. Create another account using the same username and email but with any of the letters with different capitalization. For example, using an "A" in place of an "a".
4. The account is created for that user, even though the email and user name technically exists but with a different letter case.

Expected Result

The user should not be able to input the same username or email regardless of the letter case of the username and email.