去除null

src/utils/storage.js

@@ -45,14 +45,14 @@ export function SetAsyncData(key, data, t = 0) {
 export function GetData(key) {
     let storage = Taro.getStorageSync(key)
     if (!storage) {
-        return {}
+        return null
     }
     if (storage.expire > 0) {
         let time = (new Date()).getTime()
         time = Number(String(time).substr(0, 10))
         if (time > storage.expire) {
             DelData(key)
-            return {}
+            return null
         }
     }
     return storage._data