Firstly huge thanks for such amazing module!
In some edge cases (like in my own) there can be a `undefined` React child. Easy to reproduce:
```js
<ReactSortable>
  {some_var ? <li>123</li> : undefined}
  <li>123</li>
</ReactSortable>
```

In such case crash happen because code can't read property of undefined object.
Just check changes that I made into `react-sortable.tsx` file you will understand what I'm trying to achieve.

I also changed this line from `const item = list[index];` to `const item = list[index] || {};` , just to be sure that if list doesn't have particular index, whole code not fail.
This two changes are made to prevent edge case crashes. In my own app I spend a lot of time to find out why sometime app is crashing.

Please, please approve this pull request!

…cies

## [6.0.2](v6.0.1...v6.0.2) (2022-01-14)

### Bug Fixes

* **remove unnecesary devdependencies:** rmeove innecesary devDependencies ([1000f68](1000f68))
* infra ([1d43f97](1d43f97))