Incorrect error message displayed when logging in with unconfirmed email

Summary

After modifying an account email address in profile settings and trying to login without confirming the new email address, the flash message displayed to the user says "Invalid Login or password." This is inaccurate and confusing.

Steps to reproduce

1. Navigate to profile settings
2. Update email address
3. Log out of GitLab
4. Visit https://gitlab.com/users/sign_in and log in with the new email address

Expected behavior

The message should say, "You have to confirm your email address before continuing." This is consistent with what happened when a user first signs up on GitLab.com and tries to login without confirming their email address.

Actual behavior

The error message on login is, "Invalid Login or password."