Draft: Clear tracker attributes when finish method is executed in gui_stretch

src/Mod/Draft/draftguitools/gui_stretch.py

@@ -67,6 +67,8 @@ class Stretch(gui_base_original.Modifier):
     def Activated(self):
         """Execute when the command is called."""
         super(Stretch, self).Activated(name=translate("draft","Stretch"))
+        self.rectracker = None
+        self.nodetracker = None
         if self.ui:
             if not Gui.Selection.getSelection():
                 self.ui.selectUi(on_close_call=self.finish)
@@ -251,9 +253,9 @@ class Stretch(gui_base_original.Modifier):
 
     def finish(self, closed=False):
         """Terminate the operation of the command. and clean up."""
-        if hasattr(self, "rectracker") and self.rectracker:
+        if self.rectracker:
             self.rectracker.finalize()
-        if hasattr(self, "nodetracker") and self.nodetracker:
+        if self.nodetracker:
             for n in self.nodetracker:
                 n.finalize()
         super(Stretch, self).finish()