Docker image: non-ASCII characters in voice name trigger UnicodeEncodeError

[GilOliveira]

When using the rhasspy/wyoming-piper docker image with the following Docker compose configuration:

piper:
    container_name: piper
    image: rhasspy/wyoming-piper
    volumes:
      - './piper:/data'
    command: --voice "pt_PT-tugão-medium"

The non-unicode ã character in the voice name is triggering the following error:

Traceback (most recent call last):
  File "/usr/lib/python3.9/runpy.py", line 197, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "/usr/lib/python3.9/runpy.py", line 87, in _run_code
    exec(code, run_globals)
  File "/usr/local/lib/python3.9/dist-packages/wyoming_piper/__main__.py", line 193, in <module>
    asyncio.run(main())
  File "/usr/lib/python3.9/asyncio/runners.py", line 44, in run
    return loop.run_until_complete(main)
  File "/usr/lib/python3.9/asyncio/base_events.py", line 642, in run_until_complete
    return future.result()
  File "/usr/local/lib/python3.9/dist-packages/wyoming_piper/__main__.py", line 161, in main
    await process_manager.get_process()
  File "/usr/local/lib/python3.9/dist-packages/wyoming_piper/process.py", line 114, in get_process
    ensure_voice_exists(
  File "/usr/local/lib/python3.9/dist-packages/wyoming_piper/download.py", line 137, in ensure_voice_exists
    with urlopen(file_url) as response, open(
  File "/usr/lib/python3.9/urllib/request.py", line 214, in urlopen
    return opener.open(url, data, timeout)
  File "/usr/lib/python3.9/urllib/request.py", line 517, in open
    response = self._open(req, data)
  File "/usr/lib/python3.9/urllib/request.py", line 534, in _open
    result = self._call_chain(self.handle_open, protocol, protocol +
  File "/usr/lib/python3.9/urllib/request.py", line 494, in _call_chain
    result = func(*args)
  File "/usr/lib/python3.9/urllib/request.py", line 1389, in https_open
    return self.do_open(http.client.HTTPSConnection, req,
  File "/usr/lib/python3.9/urllib/request.py", line 1346, in do_open
    h.request(req.get_method(), req.selector, req.data, headers,
  File "/usr/lib/python3.9/http/client.py", line 1255, in request
    self._send_request(method, url, body, headers, encode_chunked)
  File "/usr/lib/python3.9/http/client.py", line 1266, in _send_request
    self.putrequest(method, url, **skips)
  File "/usr/lib/python3.9/http/client.py", line 1104, in putrequest
    self._output(self._encode_request(request))
  File "/usr/lib/python3.9/http/client.py", line 1184, in _encode_request
    return request.encode('ascii')
UnicodeEncodeError: 'ascii' codec can't encode character '\xe3' in position 53: ordinal not in range(128)