Incomplete User creation prevents login

[rpcross]

In some circumstances, new Users have username but no email set. Email should always be the same as username since it is used for OIDC authentication. As of 2024-07-16 there are 208 such Users. Some as recent as 3 months ago. Many are quite old, corresponding to usernames that aren't email addresses, old style datatracker logins.

On login the user sees Server Error (500)
Logs: [04/Jul/2024:01:18:37 +0000] "GET /oidc/callback/?code=7f0255f99d744957acd210e50d480d85&state=2P6uAFo3gkXfEGDicYwWb4tk9RjSg62z HTTP/1.1" 500 145 "https://mailarchive.ietf.org/" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 Safari/537.36"