fix：DEFECT-660 平台定制时登录页背景图片登陆时未生效

@@ -46,7 +46,7 @@
     },
   ]);
   const getLogo = computed(() => {
-    return userStore.platInfo?.logo;
+    return userStore.platInfo?.background;
   });
   const getTitle = computed(() => {
     // 设置icon