更新 session_key获取逻辑

miniprogram/app.js

@@ -31,7 +31,6 @@ App({
     wx.cloud.init({
       traceUser: true
     })
-    wxSetSessionKey()
     this.globalData = {}
   },
 })

miniprogram/pages/index/index.js

@@ -22,6 +22,7 @@ Page({
   },
 
   async login() {
+    wxSetSessionKey()
     let res1 = await postApi("/user/wx/openId/login", {
       openId: wx.getStorageSync('openId')
     })