Update media.less

In Firefox, your images are leaving their container. But while you set the .pull-left inline, I can't fix it in this less file.
So this patch is just to show you, where your styling has a fault.
Greetings

![css inline wrong](https://cloud.githubusercontent.com/assets/1620425/2913047/d7d15b0a-d685-11e3-958b-a2425cb28512.png)