Heartbeats aren't received when using WebRTC

[therocode]

It seems to me like heartbeats don't work when default-features = false and the feature "use-webrtc" is enabled.

If I toggle back to not using WebRTC then I see them arrive between both client and server, and when I toggle WebRTC back on for both client/server then they don't manage to receive them.

I have added prints in my local fork to verify what is happening and the net.send(handle, Packet::new()).unwrap(); line that sends the heartbeats is reached. However, the receiving routine in Ok(packet) => { ... packet read here... in receive_packets is never triggered on the opposite end. This is seen accordingly on both client and server.

Could this be due to how the heartbeats are not turbulence messages and pure UDP (as per the heartbeats readme file)