兼容停梯时间，恢梯时间为null的情况下报错问题

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

@@ -164,10 +164,13 @@ public class MaintenanceRecordController {
 
     private MtRecordResponse getMtRecordResponse(@RequestBody @Val MtRecordRequest request) {
         MtRecordResponse entity = maintenanceRecordService.infoById(request);
-        String repairDuration = maintenanceRecordService.getRepairDuration(entity.getRepairDiff());
+        String repairDuration = "";
+        if (entity.getRepairDiff() != null) {
+            repairDuration = maintenanceRecordService.getRepairDuration(entity.getRepairDiff());
+        }
         entity.setRepairDuration(repairDuration);
         Validate.notNull(entity, ValuePool.MAINTENANCE_RECORD_NOT_EXIST);
-        /**
+        /*
          * 维保项id:0/1/2, 0:无需保养，1：已保养，2：需要更换
          * 保养项目  用键值对的方式存储，如(1:0,2:1,3:1...)
          */

lift-business-service/src/main/java/cn/com/ty/lift/business/maintenance/dao/entity/model/response/MtRecordResponse.java

@@ -72,7 +72,7 @@ public class MtRecordResponse extends MaintenanceRecord {
     /**
      * 保养时长分钟数
      */
-    private int repairDiff;
+    private Integer repairDiff;
 
     private String repairDuration;