### Environment

* Dubbo version: 2.7.5
* Operating System version: win10 or centos7
* Java version: 1.8.0
* Zookeeper version: 3.5.6

### Steps to reproduce this issue
My previous dubbo service version was 2.7.3. Today, I upgraded to 2.7.5. I found that the metadata can't be displayed all the time. The dubbo service registry in zookeeper, but zookeeper not /dubbo/metadata node path view.  If I switch back to 2.7.3 and 2.7.4.1, it can be displayed. Are there any bugs? I need help~~

xml-config:
`<dubbo:metadata-report address="zookeeper://192.168.11.100:2181?backup=192.168.11.105:2181" />`
```

*/
    private Integer qosPort;
    /**
     * Should we accept foreign ip or not?
     */
    private Boolean qosAcceptForeignIp;
    /**
     * Customized parameters
     */
    private Map<String, String> parameters;
    /**
     * Config the shutdown.wait
     */
    private String shutwait;
    private String hostname;
    /**
     * Metadata type, local or remote, if choose remote, you need to further specify metadata center.
     */
    private String metadataType;
    private Boolean registerConsumer;
    private String repository;
    public ApplicationConfig() {
    }
    public ApplicationConfig(String name) {
        setName(name);
    }
    @Parameter(key = APPLICATION_KEY, required = true, useKeyAsProperty = false)
    public String getName() {
        return name;
    }