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

### Environment

* Dubbo version: xxx
* Operating System version: xxx
* Java version: xxx

### Steps to reproduce this issue

`org.apache.dubbo.remoting.etcd.jetcd.JEtcdClientWrapper#doClose`:

```
if (globalLeaseId > 0) {
        revokeLease(this.globalLeaseId);
}
```

should be change to :

```
if (globalLeaseId != 0) {
        revokeLease(this.globalLeaseId);
}
```


Pls. provide [GitHub address] to reproduce this issue.

### Expected Result

What do you expected from the above steps？

### Actual Result

What actually happens?

If there is an exception, please attach the exception trace:

```
Just put your stack trace here!
```

maxInboundSize = Integer.valueOf(System.getProperty(GRPC_MAX_INBOUND_SIZE_KEY));
        }
        ClientBuilder clientBuilder = Client.builder()
                .loadBalancerFactory(RoundRobinLoadBalancerFactory.getInstance())
                .endpoints(endPoints(url.getBackupAddress()))
                .maxInboundMessageSize(maxInboundSize);
        return clientBuilder.build();
    }
    public Client getClient() {
        return client;
    }
    /**
     * try to get current connected channel.
     *
     * @return connected channel.
     */
    public ManagedChannel getChannel() {
        if (channel.get() == null || (channel.get().isShutdown() || channel.get().isTerminated())) {
            channel.set(newChannel(client));
        }
        return channel.get();
    }
    /**
     * find direct children directory, excluding path self,
     * Never return null.
     *
     * @param path the path to be found direct children.
     * @return direct children directory, contains zero element
     * list if children directory not exists.
     */