Remove overhang of link area

Because of a [recent change](https://github.com/guardian/frontend/pull/6912) where we position the image differently inside `list-media`

Before
![screen shot 2014-11-05 at 14 50 57](https://cloud.githubusercontent.com/assets/1607666/4919538/395cae8e-64fb-11e4-9dde-8267d31ca075.png)

After
![screen shot 2014-11-05 at 14 50 06](https://cloud.githubusercontent.com/assets/1607666/4919539/395d31ba-64fb-11e4-99dc-6f261823768b.png)