Preview users see a 401 when logging in from `/application/ready-to-join`

Describe the bug When a User with preview entitlements logs in through the login button on the /application/ready-to-join page, it gets a 401 after logging in since we're trying to redirect the user to the /portal/join-working-group but by default no org is selected.

To Reproduce Steps to reproduce the behavior:

1. Go to /application/ready-to-join
2. Login with a preview entitled user
3. A 401 page is shown

Expected behavior This isn't affecting any critical path, preview users shouldn't be logging in from there. The expected behaviour should be to just show the stand by page when the user has preview entitlements.