Created by: DannyIsFunny

【Issue】 __model__ file of Paddle-Lite consumes too much space.

model v45:
Anakin __model__ part : 32K
Paddle-Lite __model__: 330K

【Effect of Current PR】 Remove some useless op_attributes form __model__ 【Experiment】

v45.nb:
     Before: 641K 
     After: 500k
Model size will be reduced by 21.8%