Failed to send token creation email: Invalid input

[sentry-io]

Sentry Issue: CRATES-IO-BACKEND-3ZW

Failed to send token creation email: Invalid input

[Turbo87]

This was caused by an unverified "foobar at gmail dot com" email address in the database. We should probably clean up the codebase to restrict what users with unverified email addresses can do. We should also restrict the email addresses that are accepted by the endpoint that handles the email address changes.