List of steps to reproduce (step by step, including full links if applicable):

• Our team is using the same meet.wmcloud.org meeting room for our recurring meetings. Feel free to take a look: https://meet.wmcloud.org/OpenRefine-SDC-team
• Several weeks ago, one of our team members had connection issues. Since that date, we have him as a duplicate 'ghost' participant. And the meeting keeps running - while writing this ticket, the meeting has already been ongoing for 454 hours 😱

What happens?:

• Ghost participant sticks around. We can't figure out how to remove him.

What should have happened instead?:

• Jitsi room should be empty when no people are present. The chat should also be cleared then (if I recall correctly)

(I'm filing this ticket mainly because I'm worried that some process keeps running on some server somewhere, taking up resources.)