Locked out of mattermost - how to disable email verfication or reset mattermost settings

i installed GitLab Omnibus and activated mattermost in gitlab.rb.

When accessing mattermost via browser, i could create the inital user,
and the i went into settings and activated the email verfication for new users,
assuming it would not affect the user already in existence.

Now when i want to log in as admin, mattermost wants to send me an verification email,
and does not let me proceed any further. However the data center blocks outgoing emails,
so i do not recieve the verification email.

As we did not use the mattermost yet, i am cool with a solution that totally resets mattermost db/settings, however the gitlab on the server is our production instance and data wihtin gitlab must not be lost.

Assuming there is no command to just disable email verification, how can i reset the whole mattermost?

Thanks a lot in advance!

Ok, i solved it.
There is a file /var/opt/gitlab/mattermost/config.json,
where the email verification setting can be turned off.