retry test trial when there's a URLError

[carmichaelong]

Traceback (most recent call last):
  File "/usr/lib/python3.8/urllib/request.py", line 1317, in do_open
    h.request(req.get_method(), req.selector, req.data, headers,
  File "/usr/lib/python3.8/http/client.py", line 1230, in request
    self._send_request(method, url, body, headers, encode_chunked)
  File "/usr/lib/python3.8/http/client.py", line 1276, in _send_request
    self.endheaders(body, encode_chunked=encode_chunked)
  File "/usr/lib/python3.8/http/client.py", line 1225, in endheaders
    self._send_output(message_body, encode_chunked=encode_chunked)
  File "/usr/lib/python3.8/http/client.py", line 1004, in _send_output
    self.send(msg)
  File "/usr/lib/python3.8/http/client.py", line 944, in send
    self.connect()
  File "/usr/lib/python3.8/http/client.py", line 1392, in connect
    super().connect()
  File "/usr/lib/python3.8/http/client.py", line 915, in connect
    self.sock = self._create_connection(
  File "/usr/lib/python3.8/socket.py", line 787, in create_connection
    for res in getaddrinfo(host, port, 0, SOCK_STREAM):
  File "/usr/lib/python3.8/socket.py", line 914, in getaddrinfo
    for res in _socket.getaddrinfo(host, port, family, type, proto, flags):
socket.gaierror: [Errno -2] Name or service not known

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/workspace/utilsServer.py", line 498, in runTestSession
    processTrial(trial["session"], trial_id, trial_type='static', isDocker=isDocker)
  File "/workspace/utilsServer.py", line 96, in processTrial
    calibrationOptions = getCalibration(session_id,session_path,trial_type=trial_type,getCalibrationOptions=True)
  File "/workspace/utils.py", line 566, in getCalibration
    download_file(mapURL,mapLocalPath)
  File "/workspace/utils.py", line 103, in download_file
    with urllib.request.urlopen(url) as response, open(file_name, 'wb') as out_file:
  File "/usr/lib/python3.8/urllib/request.py", line 222, in urlopen
    return opener.open(url, data, timeout)
  File "/usr/lib/python3.8/urllib/request.py", line 525, in open
    response = self._open(req, data)
  File "/usr/lib/python3.8/urllib/request.py", line 542, in _open
    result = self._call_chain(self.handle_open, protocol, protocol +
  File "/usr/lib/python3.8/urllib/request.py", line 502, in _call_chain
    result = func(*args)
  File "/usr/lib/python3.8/urllib/request.py", line 1360, in https_open
    return self.do_open(http.client.HTTPSConnection, req,
  File "/usr/lib/python3.8/urllib/request.py", line 1320, in do_open
    raise URLError(err)
urllib.error.URLError: <urlopen error [Errno -2] Name or service not known>

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "app.py", line 48, in <module>
    runTestSession(isDocker=isDocker)
  File "/workspace/utilsServer.py", line 526, in runTestSession
    raise Exception('Failed status check. Stopped.')
Exception: Failed status check. Stopped.