4.0版本Tree控件删除节点出错

[daihy8759]

• I have searched the issues of this repository and believe that this is not a duplicate.

Reproduction link

Steps to reproduce

点击删除节点报错：

Uncaught TypeError: Cannot read property 'pos' of undefined
    at getTreeNodeProps (treeUtil.js:268)
    at eval (NodeList.js:211)
    at eval (List.js:213)
    at Array.map (<anonymous>)
    at List._this.renderChildren (List.js:211)
    at List.render (List.js:733)
    at finishClassComponent (react-dom.development.js:17039)
    at updateClassComponent (react-dom.development.js:16994)
    at beginWork$1 (react-dom.development.js:18505)
    at HTMLUnknownElement.callCallback (react-dom.development.js:347)
    at Object.invokeGuardedCallbackDev (react-dom.development.js:397)
    at invokeGuardedCallback (react-dom.development.js:454)
    at beginWork$$1 (react-dom.development.js:23217)

What is expected?

正常删除

What is actually happening?

出错

Environment	Info
antd	4.0.0-alpha.2
React	16.9.0
System	osx
Browser	chrome