repair delete track

qtgui/songeditor.py

@@ -124,6 +124,8 @@ class SongEditor(QtWidgets.QGraphicsScene):
         #We had these tracks in the GUI but they are gone in the export. This is track delete.
         for trackId in toDelete:
             trackStructure = self.tracks[trackId]
+            for position, switch in trackStructure.switches.items():
+                self.removeItem(switch) #switches are direct children of the scene. delete them here.
             #we don't need to delete from trackOrder here because that is cleared each time we call this function
             del self.tracks[trackId]
             self.removeItem(trackStructure) #remove from scene