Update installing guides for NO_AUTO_CREATE_USER

This is an adaption of Rafael Tinoco's Ubuntu patches to have them be compatible with both MariaDB and MySQL. The main difference from the original patches is the absence of the change for the auth algorithm. The original patch changed it to sha2 to avoid using sha1. Since MySQL 8 defaults to sha2, omitting the change should not cause major issues. Still, pointing that out to users could be discussed.