Add statuscolumn to disable_statuslines

[distek]

Hello!

This just adds statuscolumn to the list of options changed by disable_statuslines to keep the start page cleaner.

Before (Has statuscol separator):

After:

[distek]

I should note that this is assuming neovim nightly as the statuscolumn feature was just merged in within the last week or so.

[max397574]

I'd wait with this because atm this breaks startup.nvim for non nightly users