Error when trying to signup using an email address with uppercase letters

Summary

When signing up for a new account the signup form asks for your email address and "email confirmation" to protect against typos. If you include capital letters in both the form will lower case the first email field before comparing it with the email confirmation field. This prevents anyone from using capital letters in their email address.

Steps to reproduce

Signup for a new user and attempt to include a capital letter in your email address.

Expected behavior

Both fields should be lower-cased to check equivalency and verify the email address isn't already in use. Users should not be prevented from signing up if they have capital letters in their email address.

Actual behavior

User cannot sign up with email addresses that contain capital letters.

Relevant logs and/or screenshots