What is the purpose of the change

#3638
Fixed bug in this issue

Brief changelog

Modified the original error logic

Verifying this change

    ServiceConfig<DemoServiceImpl> service = new ServiceConfig<>();
    ApplicationConfig applicationConfig = new ApplicationConfig("dubbo-demo-api-provider");
    service.setVersion("1.0.1");
    service.setProtocol(new ProtocolConfig("injvm"));
    service.setApplication(applicationConfig);
    //service.setScope("local");
    service.setInterface(DemoService.class);
    service.setRef(new DemoServiceImpl());
    service.export();
    ReferenceConfig<DemoService> reference = new ReferenceConfig<>();
    reference.setVersion("1.0.1");
    reference.setProtocol("injvm");
    //reference.setScope("local");
    reference.setApplication(applicationConfig);
    reference.setInterface(DemoService.class);
    DemoService serviceImpl = reference.get();
   serviceImpl.sayHello("111");

Follow this checklist to help us incorporate your contribution quickly and easily:

• Make sure there is a GITHUB_issue field for the change (usually before you start working on it). Trivial changes like typos do not require a GITHUB issue. Your pull request should address just this issue, without pulling in other changes - one PR resolves one issue.
• Format the pull request title like [Dubbo-XXX] Fix UnknownException when host config not exist #XXX. Each commit in the pull request should have a meaningful subject line and body.
• Write a pull request description that is detailed enough to understand what the pull request does, how, and why.
• Write necessary unit-test to verify your logic correction, more mock a little better when cross module dependency exist. If the new feature or significant change is committed, please remember to add integration-test in test module.
• Run mvn clean install -DskipTests=false & mvn clean test-compile failsafe:integration-test to make sure unit-test and integration-test pass.
• If this contribution is large, please follow the Software Donation Guide.