Bottom border applied to unclassed table

Created by: mrginglymus

I can only assume that this is a rogue comma, or an entirely superfluous line: https://github.com/cambridgeuniversity/Project-Light/blob/master/stylesheets/full-stylesheet.css#L1445 + theme variations, which pollutes the unclassed <table> element to have a border. This is particularly a problem if (like drupal does) you use tables for layouts.