Fix width/height change via prop change

[pionl]

When sending first size via prop (200x300), and then changing size via prop (300x200) then the state has old size (200x300) but renderers 200x300 until onResizeStart is started (renders 300x200) until onMouseMove is triggered.

[bokuweb]

@pionl Thanks for your PR. Could you please provide reproduced sample in webpackbin if you get a chanece? https://www.webpackbin.com/bins/-Ku4nRhImIfnt9N08lGu

[pionl]

Sure thing, on this easy test you can see the incorrect size after clicking the button and using resize.

https://www.webpackbin.com/bins/-KxSjcMvj99YfILTTyS3