Highlighted notes look bad

Screen_Shot_2016-01-20_at_2.36.47_PM

https://gitlab.com/gitlab-org/gitlab-ce/issues/11867#note_3304630

The top note was the anchor (i.e., #note_3304630) so it gets a "highlighted" background. When that happens, there's not enough padding for the avatar icon and the Delete icon, and it looks weird that there's a white gap to the right of it.