IotDB cluster is not using FQDN as seed node address

In a k8s environment, when you restart a multinode iotdb server instances, instances try to connect to IPs of old instances.

I am using FQDN addresses in seed nodes list but as far as I understand, IotDB changes them to IP addresses and store them as IP addresses.

**To Reproduce**
Steps to reproduce the behavior:
1. Start 3 instances of IotDB server in k8s environment, (seed nodes list must contain FQDNs)
2. Restart all instances.
3. See logs to see IotDB tries to connect to IP address of the first run.

**Expected behavior**
IotDB should store FQDNs and convert them to IPs at startup or when first used.

**Kubernetes Environment**
- IotDB 0.12.3

在 Kubernetes 中使用三个 IoTDB 0.12.3 实例和 FQDN seed 节点重现该问题，然后检查重启日志并追踪 seed 地址的持久化位置。完成的标准是：重启后的实例保留 FQDN，并在启动时或首次使用时将其解析为当前 IP，而不是重新连接到旧的 IP 地址。

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