Fix footer isn't on the end of a long pages

On pages with a lot of podcasts the footer is somewhere in the middle of the page instead of the end. See this screenshot: https://alpha.app.net/hirnbloggade/post/7132183/photo/1

This changes brings the footer back to the bottom. This solution is not perfect, because when you zoom a lot in or out you can see some "green" besides the footer.