[PL/ComponentTransport] Don't write flux data in postTimeStepConcrete.

The flux data can / should be written using the
output class. Therefore, it is only necessary to
mention the mesh in the output section in the
project file.

ProcessLib/ComponentTransport/ComponentTransportProcess.cpp

@@ -287,7 +287,6 @@ void ComponentTransportProcess::postTimestepConcreteProcess(
 
     _surfaceflux->integrate(x, t, *this, process_id, _integration_order, _mesh,
                             pv.getActiveElementIDs());
-    _surfaceflux->save(t);
 }
 
 }  // namespace ComponentTransport