Cannot show camera in lobby if there is not microphone on this computer

### Steps to reproduce

1. Where are you starting? What can you see?
In the lobby
No mic connected to the PC
webcam connected to the PC (without mic)
I see both mic and camera muted
2. What do you click?
unmute camera

### Outcome

#### What did you expect?
The camera permission request to pop up
#### What happened instead?
The browser said that it could not find the requested device and the unmute button stayed in mute state.

### Operating system

Linux

### Browser information

Chromium (ONLY ON CHROMIUM NOT ON FF)

### URL for webapp

call.element.io

### Will you send logs?

No