Crashing while scrolling through a list of cached images, while offline

[diogowbrito]

imageFromURL crashes when scrolling through a list of images while offline.
The images were previously loaded and caches.

I was able to trace the error to an explicit bang here:
if let image = UIImage(data: data!) {

After checking for data the app seemed to work ok.

I already submitted a PR that seems to fix the issue.

[melvitax]

Thanks