User becomes admin of room though not explicitly made one

### Description

Faced this issue for the first time when I was kicking a user from multiple rooms in a community, and the community itself(they are no longer part of org.). User was granted admin rights to a particular room.

At first I thought it might have been a misclick on my part and I was cursing that UX person would think that putting a "make admin" button next to the "kick" button might be a good idea, but on further examination, it is clear that there is no way a misclick could have made them admin. At worst, they should have been banned or muted.

I am unable to remove them from the room anymore as they are an admin now (which is fine because I'm guessing it is a part of the design).

### Steps to reproduce

- No specific steps, was removing user from multiple rooms and on opening the right side panel on the user list for the particular user, the app suddenly promoted the user to admin.

Describe how what happens differs from what you expected.

- Expect to be able to kick the user, or at the very least, not make them admin :).

Logs being sent: yes


### Version information

- **Platform**: web (in-browser)

For the web app:

- **Browser**: Firefox 79.0 for Manjaro 1.0
- **OS**: Manjaro (Arch Linux base)
- **URL**: https://app.element.io/