Vim keybindings do not scroll to the selected line on `:n`

[jyn514]

When I select a line that's out of the range of the screen, the cursor will move but the viewport won't, so the cursor can end up outside the screen.

Steps to reproduce: go to https://play.rust-lang.org/?version=nightly&mode=release&edition=2018&gist=e59b183cd5eeeea326a6864c56aa5ad0 and hit :50.

[shepmaster]

Can you try it on the kitchen sink? If it fails there, then it's an upstream issue.

[shepmaster]

I'll actually keep this open to check every so often for an Ace update.