This fixes bugs where upgrading MariaDB failed to start after an upgrade
from MySQL 5.7 in Ubuntu, where auth_socket has been the default for MySQL
as well for some time now.

This was adopted from Debian where this change has been since Apr 18, 2019:
https://salsa.debian.org/mariadb-team/mariadb-10.4/-/commit/3919860b6a4ef98c098fef35fb34601adbb132b2