User blog comment:Rappy 4187/Technical Update: May 20, 2015/@comment-3388044-20150522083231/@comment-5454372-20150522092308

It can be CSS'd away: it's caused by the new updates adding extra padding to the sides of.

However, just removing the padding will cause display issues with the wordmark being too close to the edge of the page, and the local navbar hanging right off the edge of the page and over the wallpaper. You could probably fix that by repositioning the wordmark slightly and adjusting the length of the navbar.