Fix: Add Tunnel tree to GUI refresh

CityDoctorParent/Extensions/CityDoctorGUI/src/main/java/de/hft/stuttgart/citydoctor2/gui/CityDoctorController.java

@@ -1020,6 +1020,7 @@ public class CityDoctorController {
         updateTree(mainWindow.getTransportationView().getRoot());
         updateTree(mainWindow.getWaterView().getRoot());
         updateTree(mainWindow.getOtherObjectsView().getRoot());
+        updateTree(mainWindow.getTunnelView().getRoot());
         renderer.updateErrors();
     }