dubbo结合consul注册中心，kong无法通过consul的dns获取dubbo服务，但是可以获取到http服务

### Environment

* Dubbo version: 2.7.7
* Operating System version: Mac OS
* Java version: 1.8

### Steps to reproduce this issue

1. dubbo结合consul注册中心，kong无法通过consul的dns获取dubbo服务，但是可以获取到http服务。怎么通过kong调用consul上注册的dubbo服务（dubbo协议，grpc协议）

Start by reproducing the reported setup with Dubbo 2.7.7, Consul, Kong, Java 8, and macOS, comparing discovery of Dubbo, gRPC, and HTTP services through Consul DNS. Determine whether Kong can support the registered protocols and document a confirmed invocation path or the incompatibility; the issue names no source files or tests.

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