Fix promote/demote command: Jump room owner rank

Now Leader demotions go straight to Moderator, and Moderator demotions go straight to Leader. The ranks are hardcoded because both the symbol and name are subject to change, so there is no safe way to get the symbols from config.

The command now works as intended, test:
Popsickles was promoted to Leader by Joim.
(Popsickles was demoted to Voice by Joim.)
Popsickles was promoted to Driver by Joim.
Popsickles was promoted to Moderator by Joim.
(Popsickles was demoted to Driver by Joim.)
(Popsickles was demoted to Voice by Joim.)
Popsickles was promoted to Driver by Joim.
Popsickles was promoted to Moderator by Joim.
Popsickles was promoted to Leader by Joim.
(Popsickles was demoted to Moderator by Joim.)
Popsickles was promoted to Leader by Joim.
Popsickles was promoted to Administrator by Joim.
(Popsickles was demoted to Leader by Joim.)
(Popsickles was demoted to Moderator by Joim.)