fix fixtures redirect

Bug fix:
Clicking on any fixture on the football fixtures page (http://www.theguardian.com/football/premierleague/fixtures) takes the user to the results page rather than the specific fixture page.

Reason: match was not found by its date

![](http://media.giphy.com/media/Rk5z7Me51T4ju/giphy.gif)
@jamesgorrie made the same comment to me a bit earlier. I've added the date back and retested, it seems to work as expected still.