Always delete uploaded file on error

The file path was never going to be 'tmp/product_import', so I guess it never deleted the file.
Hmm but shouldn't we clean up on success too? I suppose the tmp dir will be cleaned up eventually, and maybe we want to keep them for debugging purposes.

app/models/product_import/product_importer.rb

@@ -287,8 +287,6 @@ module ProductImport
     end
 
     def delete_uploaded_file
-      return unless @file.path == Rails.root.join("tmp/product_import").to_s
-
       File.delete(@file)
     end