Fix bug
Fix bug

Eric's fixes in c00ea10b0a700e69003b860b5dbcc337d7b00e4d meant that
some of the code that already existed to reuse objects would actually
be run for the first time. Naturally, there were some bugs; namely, I
was storing a filename (instead of a File object) in `_file` and a bad
else clause.

FundedByMe/django-imagekit,tawanda/django-imagekit,tawanda/django-imagekit,pcompassion/django-imagekit,pcompassion/django-imagekit,pcompassion/django-imagekit,FundedByMe/django-imagekit