[Bug Report] TypeError: chart.pieLabel is not a function

### VUX version
2.9.3

### OS/Browsers version
window7.1

### Vue version
2.5.22

### Code

```html

JS

renderChart ({ chart }) {
...
chart.pieLabel({
sidePadding: 75,
label1: function label1(data) {
return {
text: data.memo,
fill: '#808080'
};
},
label2: function label2(data) {
return {
fill: '#000000',
text: '$' data.amount.toFixed(2),
fontWeight: 500,
fontSize: 10
};
}
});
...
}

```

### Steps to reproduce
1、在项目中使用F2中的例子
https://antv.alipay.com/zh-cn/f2/3.x/demo/pie/pie-with-label.html
2、查看控制台

3、我尝试修改node_moudules中的 v-chart.vue文件中
import F2 from '@antv/f2'
改为
import F2 from "@antv/f2/lib/index-all";
该报错消失

### What is Expected?
修复该bug

### What is actually happening?
等待中。。。