export_xlsx with file_path instead of url

lib/tallty_import_export/export.rb

@@ -55,8 +55,7 @@ module TalltyImportExport
         FileUtils.mkdir_p(file_path) unless Dir.exist?(file_path)
         file_name = "#{Time.now.strftime('%Y%m%d%H%M%S')}#{@filename}.xlsx"
         pack.serialize(File.join(file_path, file_name))
-        url = ActionController::Base.helpers.asset_url("/export/#{file_name}")
-        return url
+        return "/export/#{file_name}"
       end
     end