Username taken

I wanted to register with Gitlab via github, using the same user name. Mistakenly a wrong email address was set at github. I corrected that, but gitlab keeps sending the verification email to the old address, where it doesn’t arrive. Also, my wished username is “taken” now, which wasn’t the case before I started the process.
How can I reset this, to start over again and register at Gitlab with github, this time with correct email address?

I also tried revoking access from gitlab in github under “Authorized OAuth Apps”. This leads to new question for authorization in the gitlab register process. But still, my old email address is used for the verification. Is this an gitlab issue (username already in database with old email address)? Or is github transmitting my old address out of some reason? For the latter I have nor reason to think so:

  1. I receive all github notifications, also about gitlab asking for permission, on my new email address.
  2. The username is still “taken” in gitlab, although the access is revoked and at the moment not re-requested. So, there must be some remains of my previous trials in the database of gitlab. Who can I ask to delete this?

Ok, and one more info:
The user page exists, shows an “Unconfirmed user”. So, definately the problem is on gitlab side: gitlab set up this user, obviously with the wrong email address, and now i cannot confirm it.

Now I found this:

Seems to be solved now and unconfirmed users get deleted after 7 days.
I will just wait for this to happen.