previous if -> while

src/Hotline/FlowEngine/Workflows/WorkflowDomainService.cs

@@ -1244,7 +1244,7 @@ namespace Hotline.FlowEngine.Workflows
             if (prevStep == null)
                 throw UserFriendlyException.SameMessage("未查询到前一节点");
 
-            if (prevStep.IsCountersignEndStep)
+            while (prevStep.IsCountersignEndStep)
             {
                 countersignStartStep = workflow.Steps.FirstOrDefault(d => d.Id == prevStep.CountersignStartStepId);
                 prevStep = countersignStartStep ?? throw new UserFriendlyException("未查询到对应会签开始节点");