Suppress numbering on promoted links.

![screen shot 2014-01-10 at 11 05 45 am](https://f.cloud.github.com/assets/833317/1888717/1cdae6c0-7a11-11e3-8db8-f2bb25ea2fa5.png)

Probably a better fix is to figure out why `template_helpers.replace_render` isn't doing its job of setting `num = ""`, but this is easier and works.

:eyeglasses: @shlurbee @ehrmann