Fix T45504: Redo popup fails to update sapling UI

Referenced by issue blender/blender#45504, F6 redo_last popup doesn't redraw when attributes change

add_curve_sapling/__init__.py

@@ -396,6 +396,10 @@ class AddTree(bpy.types.Operator):
     def poll(cls, context):
         return context.mode == 'OBJECT'
 
+    def check(self, context):
+        # TODO, should check exact vars which require redraw
+        return True
+
     def draw(self, context):
 
         layout = self.layout