It might be that people try to register email addresses that they don't own. Then if the actual owner tries to add this email address, she should not get a unique constraint violation. Instead the email will be re-used.
Is this a security issue? Because we re-use the nonce? 🤔
I really don't understand why, but apparently `wrapper.html()` does some
re-rendering which in our cases fixes the tests, because we reach the
new sub component in the DOM tree.
