Fix bug where smallImageUrls was null and causing Picasso to crash

https://trello.com/c/T5Rzu7yP/56-search-pesto-chicken-pizza-and-you-get-a-null-pointer-on-smallimageuri-in-newrecipeadapter-for-picasso
I think for a user standpoint, we need to change the drawables that we use. Above, the placeholder image is the launcher icon and here it is too so if the smallimageurl is null, the user will not see a difference and think the icon is still loading. Android includes some icons that might fit this situation where an image is not available that we can use. Or we could change the loading state to some sort of "loading image" or progressbar to use instead of the launcher (should probably do this anyway).