Fix for unbalanced <ol> tags

The Ubuntu UK podcast feed was crashing newsbeuter. This seems to fix things.

The feed URL is http://feeds.feedburner.com/UbuntuUkPodcastOgg-high?format=xml - I they're on their mid-season break now so it should remain pretty static for a while to test with. The problem seems to be due to the unbalanced ol tags (missing a closing /ol)