Normalize_emails：无法将电子邮件地址从 user+x@gmail.com 更改为 user@gmail.com

[supermathie (Michael Brown)]

@RGJ

If the user tries to change the email and the normalized email addresses are the same, it should simply change it without any further process.

This is dangerous if applied to any email provider, but if we limit it to gmail addresses this is fine.