Make some mini iframes higher, to avoid cutting off content

On my machine (Linux, Firefox 34.0.5), two mini iframe groups look like this:

![cutoff](https://cloud.githubusercontent.com/assets/81277/5343632/09740c90-7f08-11e4-945e-3c44a82b61d2.png)

I figure this is a font issue, where you had access to different fonts which fit the texts in two lines. Since I think the additional white on machines where the text indeed is in two lines can't hurt, I made this small modification. Please see whether or not it is useful.

I explicitly agree to the CC-0 license for my contribution :-D