fixed： 退回默认指派到原办理人

src/Hotline/FlowEngine/Workflows/WorkflowDomainService.cs

@@ -2086,6 +2086,8 @@ namespace Hotline.FlowEngine.Workflows
             {
                 EBusinessType.Seat => ECounterSignType.Center,
                 EBusinessType.Send => ECounterSignType.Center,
+                EBusinessType.CenterMonitor => ECounterSignType.Center,
+                EBusinessType.CenterLeader => ECounterSignType.Center,
                 EBusinessType.Department => ECounterSignType.Department,
                 EBusinessType.DepartmentLeader => ECounterSignType.Department,
                 EBusinessType.File => null,
@@ -2889,7 +2891,7 @@ namespace Hotline.FlowEngine.Workflows
             newStep.StepExpiredTime = expiredTime;
             newStep.InitId();
 
-            newStep.Assign(step);
+            newStep.Assign(step, EFlowAssignType.User);
 
             stepConfig?.Invoke(workflow, stepDefine, step, newStep);