message: Fix locale_id for older versions of OS X (<= 10.11)
  This fixes a regression introduced in
diff: @@ -47,7 +47,7 @@ pub fn set_locale_environment() {
  let identifier: *const Object = msg_send![locale, localeIdentifier];
  let identifier_str = nsstring_as_str(identifier).to_owned();
  let _ : () = msg_send![identifier, release];
  - identifier_str
  + identifier_str + ".UTF-8"
  };
  let _ : () = msg_send![locale, release];
  locale_id
  