
### 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);
                }
                */
            }
        }
    };
```

}
            String[] methods = Wrapper.getWrapper(interfaceClass).getMethodNames();
            if (methods.length == 0) {
                logger.warn("No method found in service interface " + interfaceClass.getName());
                map.put(METHODS_KEY, ANY_VALUE);
            } else {
                map.put(METHODS_KEY, StringUtils.join(new HashSet<String>(Arrays.asList(methods)), COMMA_SEPARATOR));
            }
        }
        map.put(INTERFACE_KEY, interfaceName);
        AbstractConfig.appendParameters(map, getMetrics());
        AbstractConfig.appendParameters(map, getApplication());
        AbstractConfig.appendParameters(map, getModule());
        // 
        // 
        AbstractConfig.appendParameters(map, consumer);
        AbstractConfig.appendParameters(map, this);
        MetadataReportConfig metadataReportConfig = getMetadataReportConfig();
        if (metadataReportConfig != null && metadataReportConfig.isValid()) {
            map.putIfAbsent(METADATA_KEY, REMOTE_METADATA_STORAGE_TYPE);
        }
        Map<String, AsyncMethodInfo> attributes = null;
        if (CollectionUtils.isNotEmpty(getMethods())) {
            attributes = new HashMap<>();
            for (MethodConfig methodConfig : getMethods()) {
                AbstractConfig.appendParameters(map, methodConfig, methodConfig.getName());
                String retryKey = methodConfig.getName() + ".retry";
                if (map.containsKey(retryKey)) {
                    String retryValue = map.remove(retryKey);
                    if ("false".equals(retryValue)) {