fix: 修复告警历史记录函数中的空返回情况

src/modules/network_element/fetch_link/alarm.go

@@ -15,6 +15,7 @@ func AlarmHistory(neInfo model.NeInfo) ([]map[string]any, error) {
 	// 网元参数配置信息
 	neUrl := fmt.Sprintf("http://%s:%d/api/rest/faultManagement/v1/elementType/%s/objectType/alarms", neInfo.IP, neInfo.Port, strings.ToLower(neInfo.NeType))
 	resBytes, err := fetch.Get(neUrl, nil, 60_000)
+	var resData []map[string]any
 	if err != nil {
 		errStr := err.Error()
 		logger.Warnf("AlarmHistory Get \"%s\"", neUrl)
@@ -24,8 +25,11 @@ func AlarmHistory(neInfo model.NeInfo) ([]map[string]any, error) {
 		}
 	}
 
+	if len(resBytes) == 0 {
+		return resData, nil
+	}
+
 	// 序列化结果
-	var resData []map[string]any
 	err = json.Unmarshal(resBytes, &resData)
 	if err != nil {
 		logger.Errorf("AlarmHistory Unmarshal %s", err.Error())