perf(views): 优化“环境监控”一级分组查询逻辑

src/views/env-monitor/EnvMonitor.vue

@@ -279,9 +279,19 @@ const addMonitoringPoint = () => {
 };
 const addAllGatewayList = (value: number) => {
   handleRequest(async () => {
-    const data = await getDeviceGroupList({
-      parentId: value,
-    });
+    let item;
+    if (value === -1) {
+      item = {
+        parentId: value,
+        haveChild: true,
+      };
+    } else {
+      item = {
+        parentId: value,
+      };
+    }
+
+    const data = await getDeviceGroupList(item);
     if (data.length) {
       if (value === -1) {
         oneDeviceGroup.value = data;