修改bug

amos-boot-system-tzs/amos-boot-module-jg/amos-boot-module-jg-biz/src/main/java/com/yeejoin/amos/boot/module/jg/biz/service/impl/JgUseRegistrationServiceImpl.java

@@ -274,7 +274,7 @@ public class JgUseRegistrationServiceImpl extends BaseService<JgUseRegistrationD
             } else {
                 // 驳回操作
                 jgUseRegistration.setStatus(WorkFlowStatusEnum.getMessage(taskCode).getReject());
-                jgUseRegistration.setPromoter(null);
+                jgUseRegistration.setPromoter("");
             }
             if (isFirst){
                buildTask(jgUseRegistration, workflowResultDto);