Не может добавить PPA с помощью add-apt-repository: поддержка SSL, не доступная

Каждый раз, когда я пытаюсь добавить любой PPA для установки любого материала, я получаю следующую ошибку:

nikunj@nikunj-DL-H61MXE-V:~$ sudo add-apt-repository ppa:ravefinity-project/ppa
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/softwareproperties/ppa.py", line 326, in get_ppa_info
    ret = get_ppa_info_from_lp(user, ppa)
  File "/usr/lib/python3/dist-packages/softwareproperties/ppa.py", line 91, in get_ppa_info_from_lp
    return get_info_from_lp(lp_url)
  File "/usr/lib/python3/dist-packages/softwareproperties/ppa.py", line 87, in get_info_from_lp
    return _get_https_content_py3(lp_url)
  File "/usr/lib/python3/dist-packages/softwareproperties/ppa.py", line 101, in _get_https_content_py3
    lp_page = urllib.request.urlopen(request, cafile=LAUNCHPAD_PPA_CERT)
  File "/usr/lib/python3.4/urllib/request.py", line 148, in urlopen
    raise ValueError('SSL support not available')
ValueError: SSL support not available

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/bin/add-apt-repository", line 122, in <module>
    shortcut = shortcut_handler(line)
  File "/usr/lib/python3/dist-packages/softwareproperties/SoftwareProperties.py", line 841, in shortcut_handler
    ret = factory(shortcut)
  File "/usr/lib/python3/dist-packages/softwareproperties/ppa.py", line 391, in shortcut_handler
    return PPAShortcutHandler(shortcut)
  File "/usr/lib/python3/dist-packages/softwareproperties/ppa.py", line 355, in __init__
    info = get_ppa_info(self.shortcut)
  File "/usr/lib/python3/dist-packages/softwareproperties/ppa.py", line 338, in get_ppa_info
    _get_suggested_ppa_message(user, ppa))
  File "/usr/lib/python3/dist-packages/softwareproperties/ppa.py", line 295, in _get_suggested_ppa_message
    lp_user = get_info_from_lp(LAUNCHPAD_USER_API % user)
  File "/usr/lib/python3/dist-packages/softwareproperties/ppa.py", line 87, in get_info_from_lp
    return _get_https_content_py3(lp_url)
  File "/usr/lib/python3/dist-packages/softwareproperties/ppa.py", line 101, in _get_https_content_py3
    lp_page = urllib.request.urlopen(request, cafile=LAUNCHPAD_PPA_CERT)
  File "/usr/lib/python3.4/urllib/request.py", line 148, in urlopen
    raise ValueError('SSL support not available')
ValueError: SSL support not available