[desktop] Requests may error with "__str__ returned non-string (type Error" if cert validation fails

% ./build/env/bin/hue python
>>> import requests
>>> requests.put('https://localhost:20102/webhdfs/v1/tmp/hue_tests_1443126563.82?permission=0777&op=MKDIRS&user.name=hue&doas=hue')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/erickt/projects/hue/hue/build/env/lib/python2.7/site-packages/requests-2.6.0-py2.7.egg/requests/api.py", line 121, in put
    return request('put', url, data=data, **kwargs)
  File "/Users/erickt/projects/hue/hue/build/env/lib/python2.7/site-packages/requests-2.6.0-py2.7.egg/requests/api.py", line 50, in request
    response = session.request(method=method, url=url, **kwargs)
  File "/Users/erickt/projects/hue/hue/build/env/lib/python2.7/site-packages/requests-2.6.0-py2.7.egg/requests/sessions.py", line 464, in request
    resp = self.send(prep, **send_kwargs)
  File "/Users/erickt/projects/hue/hue/build/env/lib/python2.7/site-packages/requests-2.6.0-py2.7.egg/requests/sessions.py", line 576, in send
    r = adapter.send(request, **kwargs)
  File "/Users/erickt/projects/hue/hue/build/env/lib/python2.7/site-packages/requests-2.6.0-py2.7.egg/requests/adapters.py", line 370, in send
    timeout=timeout
  File "/Users/erickt/projects/hue/hue/build/env/lib/python2.7/site-packages/requests-2.6.0-py2.7.egg/requests/packages/urllib3/connectionpool.py", line 544, in urlopen
    body=body, headers=headers)
  File "/Users/erickt/projects/hue/hue/build/env/lib/python2.7/site-packages/requests-2.6.0-py2.7.egg/requests/packages/urllib3/connectionpool.py", line 344, in _make_request
    self._raise_timeout(err=e, url=url, timeout_value=conn.timeout)
  File "/Users/erickt/projects/hue/hue/build/env/lib/python2.7/site-packages/requests-2.6.0-py2.7.egg/requests/packages/urllib3/connectionpool.py", line 314, in _raise_timeout
    if 'timed out' in str(err) or 'did not complete (read)' in str(err):  # Python 2.6
TypeError: __str__ returned non-string (type Error)

requests.exceptions.SSLError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:590)