PyCurl: 'GnuTLS recv error (-9): A TLS packet with unexpected length was received.'

curl.py

from __future__ import print_function
import pycurl


print(pycurl.version)


c = pycurl.Curl()
c.setopt(pycurl.URL, 'https://packages.graylog2.org/repo/debian/dists/trusty/0.92/binary-amd64/Packages')
c.setopt(pycurl.PROXY, 'my_proxy')
c.setopt(pycurl.PROXYPORT, 8080)
c.setopt(pycurl.PROXYUSERPWD, 'xxx:yyy')
c.setopt(pycurl.HTTPPROXYTUNNEL, 1)
c.perform()
print("HTTP-Status-Code: ", c.getinfo(pycurl.HTTP_CODE))

"""
-----------
# python curl.py
PycURL/7.19.3 libcurl/7.35.0 GnuTLS/2.12.23 zlib/1.2.8 libidn/1.28 librtmp/2.3
Traceback (most recent call last):
  File "curl.py", line 14, in <module>
    print(c.perform())
pycurl.error: (56, 'GnuTLS recv error (-9): A TLS packet with unexpected length was received.')
-----------

After 
'apt-get install libcurl4-openssl-dev libssl-dev libpython-dev' 
and
'sudo pip install pycurl --upgrade'
-----------
# python curl.py 
PycURL/7.21.5 libcurl/7.35.0 OpenSSL/1.0.1f zlib/1.2.8 libidn/1.28 librtmp/2.3
HTTP-Status-Code:  302
-----------
"""