Confirm register workflow stuck when modifying password before confirmation #176

We came across this issue while our email gateway was stuck and therefore emails got delayed.

Steps to reproduce

• submit registration
• submit another registration with same email but different password
• click confirmation link in first email
  => redirected to expiration page
• click confirmation link in second email
  => redirected to error page

Expected behavior
User should either be activated or should be send to expiration page. In current setup user is lost in error page and doesn't know what to do next.

What do you see instead
Redirect to error page.

Line in question is https://github.com/modxcms/Login/blob/master/core/components/login/controllers/web/ConfirmRegister.php#L135

MODX 2.8.3
Login 1.9.10
PHP 7.4