线元数据问题修复

blade-service/blade-business/src/main/java/org/springblade/business/service/impl/MileagexyService.java

@@ -166,7 +166,7 @@ public class MileagexyService  extends BaseServiceImpl<MileagexyMapper, Mileagex
         if(result.size()>0){
             return result.get(0);
         }else{
-            return new Mileagexy();
+            return null;
         }
     }