Fix setting Media.path_key on JwPlatform import.
Fix setting Media.path_key on JwPlatform import.

This is a hacky fix for code that is going to be retired very soon, and
will make processing video on JwPlatform hobble along until we can
retire it instead of being completely broken as it is now.

nburka/site,silverorange/site,nburka/site,silverorange/site