Fix sorting on project landing page
Fix sorting on project landing page

We returned 0 instead of dict with values set to 0 if data wasn't
available. It didn't break on other landing pages but project page,
because data is always available.

m8ttyB/pontoon,Osmose/pontoon,mozilla/pontoon,participedia/pontoon,vivekanand1101/pontoon,Osmose/pontoon,mathjazz/pontoon,yfdyh000/pontoon,vivekanand1101/pontoon,Osmose/pontoon,participedia/pontoon,sudheesh001/pontoon,mathjazz/pontoon,mastizada/pontoon,m8ttyB/pontoon,mozilla/pontoon,jotes/pontoon,vivekanand1101/pontoon,mozilla/pontoon,jotes/pontoon,vivekanand1101/pontoon,yfdyh000/pontoon,mastizada/pontoon,mastizada/pontoon,mathjazz/pontoon,mozilla/pontoon,mathjazz/pontoon,Osmose/pontoon,m8ttyB/pontoon,jotes/pontoon,m8ttyB/pontoon,mathjazz/pontoon,mastizada/pontoon,yfdyh000/pontoon,sudheesh001/pontoon,sudheesh001/pontoon,jotes/pontoon,mozilla/pontoon,participedia/pontoon,yfdyh000/pontoon,sudheesh001/pontoon,participedia/pontoon