fix(views): 修复预览时报错的问题

src/views/Preview.vue

@@ -185,7 +185,7 @@ const open = async () => {
       if(!ret.data.height){ret.data.height= 1080};
       meta2d.open(ret.data);
 
-      if (meta2d.store.data.dataPoints.length) {
+      if (meta2d.store.data.dataPoints?.length) {
         getRealTimeData()
       }
     }