I find the correct SQL query:
UPDATE mdl_config SET value = 0 WHERE name = 'loginhttps';
so it's the same but one must to add ";" character at the end of the command.
This is maybe an issue on the MySQL too.
Installing and upgrading help
Can't login after switching to https-login
Müzakirə kilidlənib, beləliklə ona cavab vermək artıq mümkün deyil.