fix(bpm): 发起用户可能没有部门

发起用户可能没有部门，导致查询部门信息时报错

Signed-off-by: 今晚打老虎 <fengjiajie11@qq.com>

yudao-module-bpm/yudao-module-bpm-biz/src/main/java/cn/iocoder/yudao/module/bpm/controller/admin/task/BpmProcessInstanceController.java

@@ -135,7 +135,7 @@ public class BpmProcessInstanceController {
                 processDefinitionService.getProcessDefinitionBpmnModel(processInstance.getProcessDefinitionId()));
         AdminUserRespDTO startUser = adminUserApi.getUser(NumberUtils.parseLong(processInstance.getStartUserId())).getCheckedData();
         DeptRespDTO dept = null;
-        if (startUser != null) {
+        if (startUser != null && startUser.getDeptId() != null) {
             dept = deptApi.getDept(startUser.getDeptId()).getCheckedData();
         }
         return success(BpmProcessInstanceConvert.INSTANCE.buildProcessInstance(processInstance,