Update 13.02 to 13.02.1 failed

I tried to update through the web-version from version 13.02 to 13.02.1.
The update procedure stopped while trying to download the new version. After a while i got this.
That was two days ago. I don’t think it will ever finish.
The update procedure made a backup first.
How can I restore this backup? (I can access my nextcloud with PuTTY)
Is there some documentation about this topic?
Thanks for help

I don’t even get as far as this: Nextcloud updater does not see the new update (13021 > 1303), Update Alert (13.0.2) but not update available .

NOTE: According to Nextcloud 13.0.3 and 12.0.8 available the update was postponed.

Problem solved:

sudo -s
sudo -u www-data php /var/www/nextcloud/occ maintenance:mode --off

A tribute to the excellent documentation and the wealth of knowledge on display on https://www.c-rieger.de/
Thank you very much Carsten Rieger