
### Environment

* Dubbo version: 2.7.4.1

### Steps to reproduce this issue

在dubbo正常启动的时候，会出现很多一样的警告
```
2020-03-11 22:56:34.344 [Finalizer] [WARN] com.alibaba.dubbo.config.AbstractConfig -  [DUBBO] ReferenceConfig(null) is not DESTROYED when FINALIZE, dubbo version: 2.6.4, current host: 192.168.31.245
2020-03-11 22:56:34.345 [Finalizer] [WARN] com.alibaba.dubbo.config.AbstractConfig -  [DUBBO] ReferenceConfig(null) is not DESTROYED when FINALIZE, dubbo version: 2.6.4, current host: 192.168.31.245
2020-03-11 22:56:34.345 [Finalizer] [WARN] com.alibaba.dubbo.config.AbstractConfig -  [DUBBO] ReferenceConfig(null) is not DESTROYED when FINALIZE, dubbo version: 2.6.4, current host: 192.168.31.245
```
是从下面触发了finalize()方法发出，但是现在这个里面也已经没有做任何操作了，是不是可以把finalizerGuardian去掉了？
```
 private final Object finalizerGuardian = new Object() {
        @Override
        protected void finalize() throws Throwable {
            super.finalize();

            if (!ReferenceConfig.this.destroyed) {
                logger.warn("ReferenceConfig(" + url + ") is not DESTROYED when FINALIZE");

                /* don't destroy for now
                try {
                    ReferenceConfig.this.destroy();
                } catch (Throwable t) {
                        logger.warn("Unexpected err when destroy invoker of ReferenceConfig(" + url + ") in finalize method!", t);
                }
                */
            }
        }
    };
```

}
            checkInterfaceAndMethods(interfaceClass, getMethods());
        }
        //
        serviceMetadata.setVersion(version);
        serviceMetadata.setGroup(group);
        serviceMetadata.setDefaultGroup(group);
        serviceMetadata.setServiceType(getActualInterface());
        serviceMetadata.setServiceInterfaceName(interfaceName);
        // 
        serviceMetadata.setServiceKey(URL.buildKey(interfaceName, group, version));
        ServiceRepository repository = ApplicationModel.getServiceRepository();
        ServiceDescriptor serviceDescriptor = repository.registerService(interfaceClass);
        repository.registerConsumer(
                serviceMetadata.getServiceKey(),
                serviceDescriptor,
                this,
                null,
                serviceMetadata);
        resolveFile();
        ConfigValidationUtils.validateReferenceConfig(this);
        postProcessConfig();
    }
    /**
     * Figure out should refer the service in the same JVM from configurations. The default behavior is true
     * 1. if injvm is specified, then use it
     * 2. then if a url is specified, then assume it's a remote call
     * 3. otherwise, check scope parameter
     * 4. if scope is not specified but the target service is provided in the same JVM, then prefer to make the local
     * call, which is the default behavior