GCP broken pipe error

I noticed this error when running a 50 node cluster:

```
... # After issuing command to scale up to 50 nodes (not adaptive)
dask-454ca9f7-worker-3eacd15f
Internal IP: 10.142.15.192
External IP: None
dask-454ca9f7-worker-05101041
Internal IP: 10.142.15.193
External IP: None
dask-454ca9f7-worker-59a6ca27
Internal IP: 10.142.15.194
External IP: None
dask-454ca9f7-worker-ea64bc32
Internal IP: 10.142.15.195
External IP: None
dask-454ca9f7-worker-f514eaaf
Internal IP: 10.142.15.196
External IP: None
dask-454ca9f7-worker-674c4e80
Internal IP: 10.142.15.197
External IP: None
Task exception was never retrieved
future: exception=BrokenPipeError(32, 'Broken pipe')>
Traceback (most recent call last):
File "/home/eczech/miniconda3/envs/cloudprovider/lib/python3.8/asyncio/tasks.py", line 692, in _wrap_awaitable
return (yield from awaitable.__await__())
File "/home/eczech/miniconda3/envs/cloudprovider/lib/python3.8/site-packages/distributed/deploy/spec.py", line 71, in _
await self.start()
File "/home/eczech/miniconda3/envs/cloudprovider/lib/python3.8/site-packages/dask_cloudprovider/gcp/instances.py", line 335, in start
await self.start_worker()
File "/home/eczech/miniconda3/envs/cloudprovider/lib/python3.8/site-packages/dask_cloudprovider/gcp/instances.py", line 339, in start_worker
self.internal_ip, self.external_ip = await self.create_vm()
File "/home/eczech/miniconda3/envs/cloudprovider/lib/python3.8/site-packages/dask_cloudprovider/gcp/instances.py", line 193, in create_vm
self.cluster.compute.instances()
File "/home/eczech/miniconda3/envs/cloudprovider/lib/python3.8/site-packages/googleapiclient/_helpers.py", line 134, in positional_wrapper
return wrapped(*args, **kwargs)
File "/home/eczech/miniconda3/envs/cloudprovider/lib/python3.8/site-packages/googleapiclient/http.py", line 900, in execute
resp, content = _retry_request(
File "/home/eczech/miniconda3/envs/cloudprovider/lib/python3.8/site-packages/googleapiclient/http.py", line 204, in _retry_request
raise exception
File "/home/eczech/miniconda3/envs/cloudprovider/lib/python3.8/site-packages/googleapiclient/http.py", line 177, in _retry_request
resp, content = http.request(uri, method, *args, **kwargs)
File "/home/eczech/miniconda3/envs/cloudprovider/lib/python3.8/site-packages/google_auth_httplib2.py", line 200, in request
response, content = self.http.request(
File "/home/eczech/miniconda3/envs/cloudprovider/lib/python3.8/site-packages/httplib2/__init__.py", line 1985, in request
(response, content) = self._request(
File "/home/eczech/miniconda3/envs/cloudprovider/lib/python3.8/site-packages/httplib2/__init__.py", line 1650, in _request
(response, content) = self._conn_request(
File "/home/eczech/miniconda3/envs/cloudprovider/lib/python3.8/site-packages/httplib2/__init__.py", line 1558, in _conn_request
conn.request(method, request_uri, body, headers)
File "/home/eczech/miniconda3/envs/cloudprovider/lib/python3.8/http/client.py", line 1255, in request
self._send_request(method, url, body, headers, encode_chunked)
File "/home/eczech/miniconda3/envs/cloudprovider/lib/python3.8/http/client.py", line 1301, in _send_request
self.endheaders(body, encode_chunked=encode_chunked)
File "/home/eczech/miniconda3/envs/cloudprovider/lib/python3.8/http/client.py", line 1250, in endheaders
self._send_output(message_body, encode_chunked=encode_chunked)
File "/home/eczech/miniconda3/envs/cloudprovider/lib/python3.8/http/client.py", line 1049, in _send_output
self.send(chunk)
File "/home/eczech/miniconda3/envs/cloudprovider/lib/python3.8/http/client.py", line 971, in send
self.sock.sendall(data)
File "/home/eczech/miniconda3/envs/cloudprovider/lib/python3.8/ssl.py", line 1204, in sendall
v = self.send(byte_view[count:])
File "/home/eczech/miniconda3/envs/cloudprovider/lib/python3.8/ssl.py", line 1173, in send
return self._sslobj.write(data)
BrokenPipeError: [Errno 32] Broken pipe
```

I only end up with 49 workers (and 49 worker VMs) so I believe this caused one of them not to launch.

This same error occurs in https://github.com/dask/dask-cloudprovider/issues/218.