Reset mailcow admin to `admin:moohoo`. Older mailcow: dockerized installations may find `mailcow-reset-admin.sh` in their mailcow root directory (mailcow_path).
Both "password" and "authentication_string" exist. Currently "password" is used, but better set both.
```
MariaDB [(none)]> SELECT user FROM mysql.user;
+--------------+
| user |
+--------------+
| mailcow_user | <=====
| root |
+--------------+
2 rows in set (0.00 sec)
MariaDB [(none)]> FLUSH PRIVILEGES;
MariaDB [(none)]> UPDATE mysql.user SET authentication_string = PASSWORD('gotr00t'), password = PASSWORD('gotr00t') WHERE User = 'root' AND Host = '%';
MariaDB [(none)]> UPDATE mysql.user SET authentication_string = PASSWORD('mookuh'), password = PASSWORD('mookuh') WHERE User = 'mailcow' AND Host = '%';