That source looks fine, according to at least one of our developers. The suggestion of backing up your configuration file before performing an upgrade is a very good idea - remember, the AtoM configuration file is at
/etc/nginx/sites-available/atom per the
docs here. Make sure you check the status of the service and that it is running after doing the upgrade, and you may want to restart a few other AtoM-related services as well, such as PHP-FPM, clearing the application cache, etc. Otherwise, you should be fine!