Arvados

When a user logs into Arvados for the first time, whatever she enters in the username field is stored as email as username.

This causes two issues:

1. The user can't fix her email.
2. If the user logs in using her email, a NEW account is created, with the correct email but with a numbered username

How to reproduce:

1. Create a cluster with AutoSetupNewUsers: true
2. Log into arvados with username: someuser
3. Log out.
4. Log in again, using username: someuser@mydomain.com

What you get:

1. A user with email and username set to someuser
2. A user with email set to someuser@mydomain.com and username set to someuser2