refactor:头像显示，优先显示用户信息的头像，如果没有显示微信头像，最后没有显示系统默认头像

src/pages/index/mine.vue

@@ -132,7 +132,11 @@ export default {
       return (this.student && this.student.consumeAmount) || 0
     },
     avatar() {
-      return (this.userInfo && this.userInfo.avatarUrl) || this.pic
+      return (
+        (this.student && this.student.avatarPath) ||
+        (this.userInfo && this.userInfo.avatarUrl) ||
+        this.pic
+      )
     },
     nikeName() {
       return (this.userInfo && this.userInfo.nickName) || '点击登录'