Dropdown doesn't scroll when using arrows to select item.

[Dorious]

Version

3.2.0

Environment

Mac Sierra 10.12.6, Chrome 63.0.3239.132 (or any other browser I check)

Reproduction link

https://ant.design/components/select/

Steps to reproduce

Go to https://ant.design/components/select/
Pick example with long list of Options (first on the right with 'a1' will do), and then click keyboard arrow down until you get to the results that are not visible.
It doesn't scroll/move the list :(

What is expected?

Scrolling the list.

What is actually happening?

It stays in the the same scrollTop.

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Please fix it's annoying :P It is odd because on my build it sometimes works and god knows why :( But usually it isn't.