Bug: Disconnecting typing does not appear to work

[WalrusSoup]

Disconnecting from typing listeners via the function returned from getTyping does not appear to work. The old CB will still receive events.

// Stop watching the old channel
if (this.currentChannelStopTypingUpdatesDisconnectFunction) {
    console.log('disconnecting existing handler')
    this.currentChannelStopTypingUpdatesDisconnectFunction();
}
// Watch only the new channel
this.currentChannelStopTypingUpdatesDisconnectFunction = channel.getTyping((typing) => {
    console.log('got typing events');
});

To reproduce:

1. Join the same channel
2. Have the user start typing
3. Call disconnect
4. Callback still keeps firing

[piotr-suwala]

Hello!

We've put your item in the backlog and we'll take care of this in near future :)