!785 修复目录缓存问题

src/UI/Components/SourceManage/CommonPanel.tsx

@@ -738,6 +738,7 @@ export class CommonPanel extends React.Component<ICommonPanelProps, ICommonPanel
             }
             else
                 node = node.childNodes[n];
+            if (!node) return;
             if (node.childNodes.length)
                 node.isExpanded = true;
         }