update store/modules/app.js.

state从缓存获取openid的部分，漏传了key==>OPENID，导致Cache.get(undefined)报错

Signed-off-by: 青椒麻不过花椒 <2662334834@qq.com>

store/modules/app.js

@@ -15,7 +15,7 @@ const state = {
 	backgroundColor: "#fff",
 	userInfo: Cache.get(USER_INFO)?JSON.parse(Cache.get(USER_INFO)):null,
 	uid: Cache.get(UID) || null,
-  openid: Cache.get() || null,
+    openid: Cache.get(OPENID) || null,
 	homeActive: false,
 	chatUrl: Cache.get('chatUrl') || '',
 	systemPlatform: Cache.get(PLATFORM)?Cache.get(PLATFORM):'',