fix: Not to overwrite any existed configurations in Nacos during initialization

[CH3CHO]

just in case user installs a second Higress instance to the same Nacos server and namespace.

publishConfig() {
  # $1 namespace
  # $2 configType: plural
  # $3 configName
  # $4 content
  # $5 skipWhenExisted
  case $CONFIG_STORAGE in
    nacos)
      publishNacosConfig "$@"
      ;;
    file)
      publishFileConfig "$@"
      ;;
    *)
      printf "  Unknown storage type: %s\n" "$CONFIG_STORAGE"
      exit -1
      ;;
  esac
}

[johnlanni]

LGTM