Method grouping class is declared, so it does't need to be generated by javassist. [DUBBO-635 JValidator在类名生成的类名有$，有frozen class异常](https://github.com/alibaba/dubbo/commit/e4dea029546efe9e7a6184ad528560e62303ce02) Close #504 #784
Method grouping class is declared, so it does't need to be generated by javassist.
DUBBO-635 JValidator在类名生成的类名有$，有frozen class异常
Close #504 #784