Oops, I forget to do something with this.
We kind of not need it.

We have `_cancel_ongoing_defers` that does `backend.cancel_X` for every X running.
Also we have `_cleanup_and_quit` that logs out and stops eip.

The problem with that `stop` is that if eip isn't stopped yet, then the app will quit leaving the vpn process running.
Maybe hooking this stop to the vpn stop?