无梯号电梯，导出文件夹名包含无梯号

lift-business-service/src/main/java/cn/com/ty/lift/business/maintenance/service/MaintenanceRecordService.java

@@ -912,7 +912,7 @@ public class MaintenanceRecordService extends ServiceImpl<MaintenanceRecordMappe
                 String useCompanyCode = mtRecordResponse.getUseCompanyCode();
                 projectName = StrUtil.isNotEmpty(projectName) ? projectName.replace(illegalChars, "-") : "[项目]";
                 registrationCode = StrUtil.isNotEmpty(registrationCode) ? registrationCode.replace(illegalChars, "-") : "[电梯注册代码]";
-                useCompanyCode = useCompanyCode != null ? useCompanyCode : "";
+                useCompanyCode = useCompanyCode != null ? useCompanyCode : "未设置梯号";
                 //保养单及图片文件夹 dir/i.ProjectName-RegistrationCode/
                 String imgDir = StrUtil.format("{}{}.{}-{}", dir + File.separator, useCompanyCode, projectName, registrationCode + File.separator);
                 //生成维保图片