Sporadic "Connection reset by peer" errors on GCP

Example Error:
```
Traceback (most recent call last):
File "/home/johnbradley2008_gmail_com/env/lib/python2.7/site-packages/ddsc/core/download.py", line 417, in run
return self.retry_download_loop()
File "/home/johnbradley2008_gmail_com/env/lib/python2.7/site-packages/ddsc/core/download.py", line 430, in retry_download_loop
self.download_chunk(url, headers)
File "/home/johnbradley2008_gmail_com/env/lib/python2.7/site-packages/ddsc/core/download.py", line 472, in download_chunk
self._write_response_to_file(response)
File "/home/johnbradley2008_gmail_com/env/lib/python2.7/site-packages/ddsc/core/download.py", line 482, in _write_response_to_file
for chunk in response.iter_content(chunk_size=self.bytes_per_chunk):
File "/home/johnbradley2008_gmail_com/env/lib/python2.7/site-packages/requests/models.py", line 753, in generate
raise ChunkedEncodingError(e)
ChunkedEncodingError: ("Connection broken: error(104, 'Connection reset by peer')", error(104, 'Connection reset by peer'))
```

Running the same `ddsclient download` command again worked the next time.