message: fix addr_str format bug
diff: @@ -112,7 +112,7 @@ def runserver(debug, console_log, use_reloader, address, port, timeout, workers,
  logging.info(
  "The Gunicorn 'superset runserver' command is deprecated. Please "
  "use the 'gunicorn' command instead.")
  - addr_str = ' unix:{socket} ' if socket else' {address}:{port} '
  + addr_str = f' unix:{socket} ' if socket else f' {address}:{port} '
  cmd = (
  'gunicorn '
  f'-w {workers} '
  