Checking for Field List Before Displaying it

If you have an empty form (whoops I totally did that) and attempt to display it on the front end you get an error.

![slack___ninja_forms](https://f.cloud.github.com/assets/1065372/2303498/238bd35a-a1c4-11e3-9f6b-9264e615d612.png)

Unrelated. It's my birthday. Just sayin. :)