Gentlemen, is what is seen on the screenshots something that you supposed to get? I don't quite remember what the indentation of #mw-content-text was before the "Remove contentSub from layout when empty" commit, but now it's waaay too close to the subtitle.
...Actually, the indentation was exactly the same before and after the linked commit. #contentSub's
margin: 0 0 1.4em 1em;
was accompanied by #jump-to-nav's
margin-top: -1.4em; margin-bottom: 1.4em;
After the change, the hidden #contentSub was compensated by #jump-to-nav's
margin-top: 0; margin-bottom: 1.4em;
Now #contentSub is gone, and both #jump-to-nav's margins also gone. No margin left.