Unable to get permissions for camera and microphone when using custom widget with UTL to jitsi conference room.

### Description

I'm trying to integrate a widget to my own jitsi server into a room. Creating a custom widget works, but I am unable to use camera and microphone, I get "Error obtainig microphone/camera permission" message. This is true for web client as well as desktop client.

riot.im's Jitsi widget does not have the permissions problem and works. But if I add same jitsi.riot.im URL via custom widget then I cannot set permissions as well.

### Steps to reproduce

- Add a custom widget with the URL to a custom jitsi conference room
- Try to activate microphone/camera

Logs being sent: no

### Version information

- **Platform**: web and desktop

For the web app:

- **Browser**: Chromium 83.0.4103.61, Firefox 78.0.2
- **OS**: Ubuntu 18.04
- **URL**: riot-web 1.7.1

For the desktop app:

- **OS**: Ubuntu 18.04
- **Version**: 1.7.2