use 'readTree' to parse data file

public/locales/en.json

@@ -103,6 +103,7 @@
   "node.editSubtreeDenied": "Unable to edit the subtree node",
   "node.id": "Node id",
   "node.inputVariable": "Input variables",
+  "node.invalidChildren": "Invalid number of children",
   "node.invalidGroup": "Node group '{{group}}' is not enabled",
   "node.invalidValue": "Invalid value",
   "node.invalidVariableName": "Invalid variable name, should start with a letter or underscore",

public/locales/zh.json

@@ -102,6 +102,7 @@
   "node.disabled": "禁用",
   "node.editSubtreeDenied": "不能编辑子树节点",
   "node.id": "节点标识",
+  "node.invalidChildren": "子节点数量不合法",
   "node.inputVariable": "输入变量",
   "node.invalidGroup": "节点分组 “{{group}}” 未启用",
   "node.invalidValue": "无效的值",