[Shotwell] thumbnail update

[Saturnino Garcia]

I recently bought a new computer and am in the process of transferring all
my data to my new hard drive. I backed up my shotwell database (photo.db)
and my photo directory. When I open shotwell on my new computer, there are
no thumbnails for the image (only gray boxes). The images show up fine in
the single image view though (i.e. when I double click on one of them). Is
there some way I can regenerate those thumbnails?

- Sat