ipfshttpclient pubsub subscribe ReadTimeoutError

After a few minutes listening of the pubsub topic, the following ```ReadTimeoutError``` occurs:
(ipfs version 0.4.22)

```
[strdn@workstation:~]$ python
Python 3.7.4 (default, Jul 8 2019, 18:31:06)
[GCC 7.4.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import ipfshttpclient
>>> ipfshttpclient.__version__
'0.4.12'
>>>
>>>
>>> ipfs_client = ipfshttpclient.connect("/dns/{0}/tcp/{1}/http".format("localhost", 5001))
>>> with ipfs_client.pubsub.subscribe("testtopic") as sub:
... for msg in sub:
... print(msg)
...
{'from': 'EiAbczehxo538q7gpgo7fQbgAJmyXWkcj74HlNF3z/cnCg==', 'data': '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', 'seqno': 'Fck777zgvZo=', 'topicIDs': ['testtopic']}
{'from': 'EiAbczehxo538q7gpgo7fQbgAJmyXWkcj74HlNF3z/cnCg==', 'data': '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', 'seqno': 'Fck777zgvZs=', 'topicIDs': ['testtopic']}
{'from': 'EiB6JAkt6Xnr0r60Psok6GkizOVGAosLICNRy7IXND+FZA==', 'data': 'eyJzaWduYXR1cmUiOiIweDg4YTY1ZjUwZDUwYmRjYTFmZTAyYzlhODQ3NTUzMjY4YzgxNzM4MWU0ZGM2MDg1ZDQ2OGI5MmRkN2M5ZWE2NTY2OGY2ZTZkNDRhYWM2NThhYjMzZTJjNGRjOTk0MmRhMTA4YTFjMDFiOTg3MTU1N2E1NjBjMzczM2FmMGVhODdmMWMiLCJvcmRlciI6IjB4YjBlODkyZmQ3NjRlMTNjNDQyNTdkNDhkMWMwZjJkNjM0ZDE4YjFiOThmODNmMGEyNDUyNzMxMzFlYjlmMDcxMCIsImFjY2VwdGVkIjowfQ==', 'seqno': 'FchIHlINxfI=', 'topicIDs': ['testtopic']}

Traceback (most recent call last):
File "/nix/store/wybafbmdfdvxi7y2h0f5bc58w2bvh9jb-python3.7-urllib3-1.24.3/lib/python3.7/site-packages/urllib3/response.py", line 362, in _error_catcher
yield
File "/nix/store/wybafbmdfdvxi7y2h0f5bc58w2bvh9jb-python3.7-urllib3-1.24.3/lib/python3.7/site-packages/urllib3/response.py", line 668, in read_chunked
self._update_chunk_length()
File "/nix/store/wybafbmdfdvxi7y2h0f5bc58w2bvh9jb-python3.7-urllib3-1.24.3/lib/python3.7/site-packages/urllib3/response.py", line 600, in _update_chunk_length
line = self._fp.fp.readline()
File "/nix/store/yglc8kgzmdaskyngv90y1mw96fl00pjy-python3-3.7.4/lib/python3.7/socket.py", line 589, in readinto
return self._sock.recv_into(b)
socket.timeout: timed out

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/nix/store/fz3hvv4jfw2rnmq8frdhqcikys1sx347-python3.7-requests-2.22.0/lib/python3.7/site-packages/requests/models.py", line 750, in generate
for chunk in self.raw.stream(chunk_size, decode_content=True):
File "/nix/store/wybafbmdfdvxi7y2h0f5bc58w2bvh9jb-python3.7-urllib3-1.24.3/lib/python3.7/site-packages/urllib3/response.py", line 492, in stream
for line in self.read_chunked(amt, decode_content=decode_content):
File "/nix/store/wybafbmdfdvxi7y2h0f5bc58w2bvh9jb-python3.7-urllib3-1.24.3/lib/python3.7/site-packages/urllib3/response.py", line 696, in read_chunked
self._original_response.close()
File "/nix/store/yglc8kgzmdaskyngv90y1mw96fl00pjy-python3-3.7.4/lib/python3.7/contextlib.py", line 130, in __exit__
self.gen.throw(type, value, traceback)
File "/nix/store/wybafbmdfdvxi7y2h0f5bc58w2bvh9jb-python3.7-urllib3-1.24.3/lib/python3.7/site-packages/urllib3/response.py", line 367, in _error_catcher
raise ReadTimeoutError(self._pool, None, 'Read timed out.')
urllib3.exceptions.ReadTimeoutError: HTTPConnectionPool(host='localhost', port=5001): Read timed out.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "", line 2, in
File "/nix/store/5hh2gyn903qsqnghv43rq90vsawcaslw-python3.7-ipfshttpclient-0.4.12/lib/python3.7/site-packages/ipfshttpclient/http.py", line 95, in __next__
data = next(self._response_iter)
File "/nix/store/fz3hvv4jfw2rnmq8frdhqcikys1sx347-python3.7-requests-2.22.0/lib/python3.7/site-packages/requests/models.py", line 757, in generate
raise ConnectionError(e)
requests.exceptions.ConnectionError: HTTPConnectionPool(host='localhost', port=5001): Read timed out.
```