/**
  *遍历替换属性名
  * @param city 省市区集合
  * @return [] 替换属性名结果集
*/
function eachReplaceKey(city) {
  let item=[];
  city.map(list=>{
    let newData={};
    newData.label=list.name;
    newData.value=list.name;
    if(list.sub){
      newData.children=eachReplaceKey(list.sub)
    }
    item.push(newData);
  })
    return item;
}