Remove unnecessary download_metadata.swift env var set

Author: mokagio

fastlane/Fastfile

@@ -90,7 +90,6 @@ platform :ios do
   ENV[GHHELPER_REPO = 'woocommerce/woocommerce-iOS']
   ENV['PROJECT_NAME'] = 'WooCommerce'
   ENV['PUBLIC_CONFIG_FILE'] = 'config/Version.Public.xcconfig'
-  ENV['DOWNLOAD_METADATA'] = 'fastlane/download_metadata.swift'
   ENV['PROJECT_ROOT_FOLDER'] = './'
   ENV['APP_STORE_STRINGS_FILE_NAME'] = 'AppStoreStrings.pot'
   ENV['FL_RELEASE_TOOLKIT_DEFAULT_BRANCH'] = 'trunk'