Add support for mariadbd binary

[handymenny]

Starting with MariaDB 10.5.2 the binary is named mariadbd
Reference: https://jira.mariadb.org/browse/MDEV-21303

[Berserker66]

This appears to address #83 and I'd like to see mariadb support.

[miken32]

@defanator is something wrong with this pull request that it never got accepted? Seems like a very innocuous change, that would make a big improvement for users.

Only problem I see with it is the conditional should be if cmd.split(' ', 1)[0].endswith('mysqld') or cmd.split(' ', 1)[0].endswith('mariadbd'): instead of making it only check for trailing d. Works fine for me in local testing.