OIDC does not use email claim for new accounts

[madduck]

A user created in Docspell through an OIDC login does not get an email address, even though the JWT includes the email:

{
    […]
    "docspell_collective": "ACME",
    "email": "[email protected]",
    "email_verified": true,
    "name": "Martin Krafft",
    "given_name": "Martin Krafft",
    "preferred_username": "Martin.Krafft",
    "nickname": "Martin.Krafft",
    […]
}

Especially if email_verified is true, the email field should be used for the new user.