[Dubbo-1284] Fix UT warning message when running on Java 9 (#1323)
[Dubbo-1284] Fix UT warning message when running on Java 9 (#1323)

* Fix UT warning message when running on Java 9, patch provided by @web1992  Fix #1284

fengyie007/dubbo,qtvbwfn/dubbo,JasonHZXie/dubbo,alibaba/dubbo,yuyijq/dubbo,aglne/dubbo,JasonHZXie/dubbo,dadarom/dubbo,alibaba/dubbo,qtvbwfn/dubbo,aglne/dubbo,bpzhang/dubbo,qtvbwfn/dubbo,wuwen5/dubbo,wuwen5/dubbo,fengyie007/dubbo,bpzhang/dubbo,dadarom/dubbo,qtvbwfn/dubbo,yuyijq/dubbo,lovepoem/dubbo,bpzhang/dubbo,fengyie007/dubbo,lovepoem/dubbo,aglne/dubbo,dadarom/dubbo,lovepoem/dubbo,wuwen5/dubbo