fix MenuList scrolling issue in IE11 with openMenuOnFocus option
fix MenuList scrolling issue in IE11 with openMenuOnFocus option

seems related to 30ead6d, a fix for the MenuList closing when the
scrollbar is clicked in IE11.  When the select input is refocused, the
openMenu method re-scrolls MenuList to the currently selected value,
causing the user to be unable to scroll to other values via mouse click

fixes #3342

JedWatson/react-select,JedWatson/react-select