dubbo GenericInvoke throws exception local class incompatible

[qixiaobo]

apache/dubbo#4675
since dubbo may not release as soon as possible.
Maybe we should support dubbo 2.6.x or something else?

[qixiaobo]

I should say that I make a new branch to support 2.7.x-
you can refer to https://github.com/qixiaobo/dubbo-proxy/tree/dubbo-2.6.x