Network routes are missing vehicle ids when mode is teleported in mobsim.

[Janekdererste]

In the case where a mode is routed but not simulated on the network, the plans contain NetworkRoutes for those legs. Thes routes have 'vehicleRefId="null"'. I think those routes should also have a vehicle id assigned. Because "null" is always problematic.

The simulation creates vehicles for those routes at the beginning, because they are also necessary for re-routing.