fix(report):修复因为没有找到园区概览而出现的错误。

service/report.go

@@ -137,10 +137,13 @@ func (_ReportService) InitializeNewReport(parkId string, period time.Time) (err
 func (_ReportService) RetreiveReportIndex(rid string) (*model.Report, error) {
 	reports := make([]model.Report, 0)
 	err := global.DBConn.Where(builder.Eq{"id": rid}).Find(&reports)
+	if err != nil {
+		return nil, err
+	}
 	if len(reports) > 0 {
 		return &reports[0], nil
 	} else {
-		return nil, err
+		return nil, nil
 	}
 }