Check if mediaDevices exists before using it on disconnect

[caiiiycuk]

No description provided.

[lukasIO]

@caiiiycuk thanks, would you mind changing the if clause to use optional chaining instead? navigator.mediaDevices?.removeEventListener.
To keep it consistent also for when subscribing to the event listener.
I didn't want to bother for a single line change yesterday, but as it is popping up in more places, it feels right to align with the coding style of the repo.

[caiiiycuk]

Done