mysql> select * from mdl_config where name like 'additional%';
Suggest adding the lines to config.php to set them to 'blanks' ... ie, no value.
That should allow you to login again at least and get to the config of it in the admin UX.
To be able to enter a value in one, comment out the config lines that blanked them ... no restart/reboot necessary ... just comment out or make active - which ever is the need.
Enter whatever in the form and save.
If what you put in locks you out again ... un-comment the line in config.php to blank it again. Refresh the Moodle Admin UX screen.
Even for developers, think the general advice is not to edit DB directly ... unless you really know what you are doing.
Am not a developer myself and have found that advice a pretty good idea!
BTW, there is a cfg.php script in code/admin/cli/ which is supposed to allow changing any setting it knows about.
php cfg.php --help