- [x] I have searched the [issues](https://github.com/apache/dubbo/issues) of this repository and believe that this is not a duplicate.
- [x] 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: master
* Operating System version: all platform
* Java version: all version

### Steps to reproduce this issue

1. set SystemProperty "java.net.preferIPv6Addresses" to true.
2. call org.apache.dubbo.common.utils.NetUtils#isPreferIPV6Address().
3. check the return value.

### Expected Result

org.apache.dubbo.common.utils.NetUtils#isPreferIPV6Address() will return true when SystemProperty "java.net.preferIPv6Addresses" set to true.

### Actual Result

org.apache.dubbo.common.utils.NetUtils#isPreferIPV6Address() method ignore SystemProperty "java.net.preferIPv6Addresses" and always return false
if (hostname != null && hostname.length() > 0) {
                return hostname;
            }
            InetAddress inetAddress = InetAddress.getByName(address);
            if (inetAddress != null) {
                hostname = inetAddress.getHostName();
                HOST_NAME_CACHE.put(address, hostname);
                return hostname;
            }
        } catch (Throwable e) {
            
        }
        return address;
    }
    /**
     * @param hostName
     * @return ip address or hostName if UnknownHostException
     */
    public static String getIpByHost(String hostName) {
        try {
            return InetAddress.getByName(hostName).getHostAddress();
        } catch (UnknownHostException e) {
            return hostName;
        }
    }
    public static String toAddressString(InetSocketAddress address) {
        return address.getAddress().getHostAddress() + ":" + address.getPort();
    }
    public static InetSocketAddress toAddress(String address) {
        int i = address.indexOf(':');