Method task_loop_once

tee/cocoon/FwdProxy.cpp:208–211

  }

  td::actor::Task<Action> task_loop_once() override {
    co_await do_loop();
    co_return state_ == State::Done ? Action::Finish : Action::KeepRunning;
  }

  td::actor::Task<Answer> finish(td::Status status) override {
    LOG(INFO) << "Finish: status=" << status;