Method schedule

client/ovpncli.cpp:379–394

      }

      void schedule()
      {
	timer.expires_after(period);
	timer.async_wait([this](const openvpn_io::error_code& error)
			 {
			   if (!parent || error)
			     return;
			   try {
			     parent->clock_tick();
			   }
			   catch (...)
			     {
			     }
			   schedule();
			 });
      }

    private:
      AsioTimer timer;