Remove needs of DummyUnit
The is in Transport, we need to make a special test case for COMMAND_EXIT to not check if a unit exist in slot 0 in this case. Then we can remove the DummyUnit which is useless.
The is in Transport, we need to make a special test case for COMMAND_EXIT to not check if a unit exist in slot 0 in this case. Then we can remove the DummyUnit which is useless.