Fix filenames in Firefox favourites patch again
@fmuellner 's changes in 7557912 seem to revert @mstransky 's
changes from 624402d and 8c09aad , with no explanation. As this
does seem to prevent Firefox showing up as a favourite, let's
put it back to mstransky's way and see if that fixes it.
Signed-off-by: Adam Williamson <awilliam@redhat.com>