Feature request: make web_microphone_websocket work outside localhost

[comodoro]

The web_microphone_websocket example works for localhost, but on a domain there were CORS errors from the socket.io code, e.g. Chrome:

Access to XMLHttpRequest at 'https://example.com:4000/socket.io/?EIO=3&transport=polling&t=Nu-iT4E' from origin 'https://example.com.cz:3000' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

Several recipes from SO and the socket.io docs did not work, perhaps someone with better JS knowledge might help.