server.py fails to run when system hostname is not 'localhost'

[lumberjackgames]

I'm on Ubuntu server lts with a unique hostname. When I ran server.py, I got the following error:

=====================================
Starting relay. Press Ctrl-C to exit.
=====================================
Traceback (most recent call last):
  File "server.py", line 216, in <module>
    loop.run_until_complete(futures)
  File "/usr/lib/python3.8/asyncio/base_events.py", line 616, in run_until_complete
    return future.result()
  File "server.py", line 206, in runServer
    await site.start()
  File "/home/minetest/.local/lib/python3.8/site-packages/aiohttp/web_runner.py", line 121, in start
    self._server = await loop.create_server(
  File "/usr/lib/python3.8/asyncio/base_events.py", line 1463, in create_server
    raise OSError(err.errno, 'error while attempting '
OSError: [Errno 99] error while attempting to bind on address ('::1', 8080, 0, 0): cannot assign requested address

I was able to work around this by changing 'localhost' to '127.0.0.1' on this line

I can make a PR if wanted, but just dropping this here for now in case anyone runs into this.