- [ ] I have searched the [issues](https://github.com/apache/dubbo/issues) of this repository and believe that this is not a duplicate.
- [ ] I have checked the [FAQ](https://github.com/apache/dubbo/blob/master/FAQ.md) of this repository and believe that this is not a duplicate.

### Environment

* Dubbo version: 2.7.5
* Zookeeper version: 3.4.14
* Operating System version: macos
* Java version: 1.8

### Steps to reproduce this issue

1. 按官方文档搭建provider，两种方式：annotation/xml
2. 分别配置

```xml
    <dubbo:metadata-report address="zookeeper://127.0.0.1:2181"/>
```

```java
        @Bean
        public MetadataReportConfig metadataReportConfig() {
            MetadataReportConfig metadataReportConfig = new MetadataReportConfig();
            metadataReportConfig.setAddress("zookeeper://127.0.0.1:2181");
            return metadataReportConfig;
        }
```

3. 应用正常启动
4. Consumer端正常调用
4. 观察Zookeeper节点数据，元数据节点/dubbo/metadata 未创建

### Expected Result
元数据正常上报

### Actual Result

元数据节点在Zookeeper上未创建，元数据未上报

> 将dubbo版本号更改为2.7.4.1、2.7.3，代码或配置未改动，元数据正常上报

}
    private void putRandomPort(String protocol, Integer port) {
        protocol = protocol.toLowerCase();
        if (!RANDOM_PORT_MAP.containsKey(protocol)) {
            RANDOM_PORT_MAP.put(protocol, port);
            logger.warn("Use random available port(" + port + ") for protocol " + protocol);
        }
    }
    private void postProcessConfig() {
        List<ConfigPostProcessor> configPostProcessors =ExtensionLoader.getExtensionLoader(ConfigPostProcessor.class)
                .getActivateExtension(URL.valueOf("configPostProcessor://"), (String[]) null);
        configPostProcessors.forEach(component -> component.postProcessServiceConfig(this));
    }
    /**
     * Dispatch an {@link Event event}
     *
     * @param event an {@link Event event}
     * @since 2.7.5
     */
    private void dispatch(Event event) {
        EventDispatcher.getDefaultExtension().dispatch(event);
    }
    public DubboBootstrap getBootstrap() {
        return bootstrap;
    }
    public void setBootstrap(DubboBootstrap bootstrap) {
        this.bootstrap = bootstrap;
    }
}