Remove duplicated declaration

labelme/widgets/canvas.py

@@ -30,7 +30,6 @@ class Canvas(QtWidgets.QWidget):
     drawingPolygon = QtCore.Signal(bool)
     vertexSelected = QtCore.Signal(bool)
 
-    CREATE, EDIT = 0, 1
     CREATE, EDIT = 0, 1
 
     # polygon, rectangle, line, or point