pref(utils): 优化convertFlowData初始化的判断条件

src/utils/convertFlowData.ts

@@ -11,7 +11,7 @@ export const convertFlowData = (flowData: any, useDefault = true) => {
   const nodes: any[] = [];
   const edges: any[] = [];
 
-  if (!flowData || Object.keys(flowData).length === 0) {
+  if (!flowData || Object.keys(flowData).length === 0 || flowData.main.nodeConfigs.length === 0) {
     // 如果useDefault为true且flowData为空，则返回默认的开始和结束节点
     if (useDefault) {
       return {
@@ -34,7 +34,7 @@ export const convertFlowData = (flowData: any, useDefault = true) => {
           {
             id: 'end',
             type: 'end',
-            position: { x: 1200, y: 200 },
+            position: { x: 600, y: 200 },
             data: {
               title: '结束',
               parameters: {