kubeedge's cloudcore component advertiseAddress configuration format is wrong

Created by: wenhuwang

Ks-installer Version: v3.1.0 cluster-configuration.yaml:

···
    kubeedge:
    enabled: true
    cloudCore:
      nodeSelector: {"node-role.kubernetes.io/worker": ""}
      tolerations: []
      cloudhubPort: "10000"
      cloudhubQuicPort: "10001"
      cloudhubHttpsPort: "10002"
      cloudstreamPort: "10003"
      tunnelPort: "10004"
      cloudHub:
        advertiseAddress: # At least a public IP Address or an IP which can be accessed by edge nodes must be provided
          - 10.10.52.70            # Causion!: Leave this entry to empty will cause CloudCore to exit abnormally once KubeEdge is enabled.
          - 10.10.52.71
          - 10.10.52.72
        nodeLimit: "100"

/kind bug /assign @wenhuwang