rhui-manager fails to add first repository when proxy required to access cdn.redhat.com despite proxy being configured

Issue

• rhui-manager fails with an unexpected error when trying to add first repository.

rhui (repo) => a

Loading latest entitled products from Red Hat...

An unexpected error has occurred during the last operation.
More information can be found in ~/.rhui/rhui.log.

• Contents of ~/.rhui/rhui.log file indicates a "Connection timed out":

Unexpected error caught at the shell level
Traceback (most recent call last):
  File "/usr/lib/python2.6/site-packages/rhui/tools/shell.py", line 86, in safe_listen
    self.listen(clear=first_run)
  File "/usr/lib/python2.6/site-packages/rhui/tools/shell.py", line 112, in listen
    Shell.listen(self)
  File "/usr/lib/python2.6/site-packages/rhui/common/shell.py", line 186, in listen
    item.func(*args, **item.kwargs)
  File "/usr/lib/python2.6/site-packages/rhui/tools/screens/repo.py", line 123, in add
    self.candidate_repo_manager.translate_entitlements()
  File "/usr/lib/python2.6/site-packages/rhui/tools/repo_candidates.py", line 64, in translate_entitlements
    mappings = self.cdn_api.expand_variables(e.download_url, cert.cert_filename)
  File "/usr/lib/python2.6/site-packages/rhui/tools/cdn_api.py", line 71, in expand_variables
    mappings = self._translate_next_variable({'' : url}, cert_filename)
  File "/usr/lib/python2.6/site-packages/rhui/tools/cdn_api.py", line 104, in _translate_next_variable
    substitutions = self._request_get(listing_url, cert_filename).split('\n')
  File "/usr/lib/python2.6/site-packages/rhui/tools/cdn_api.py", line 153, in _request_get
    server = self._server(cert_filename)
  File "/usr/lib/python2.6/site-packages/rhui/tools/cdn_api.py", line 211, in _server
    server.connect()
  File "/usr/lib64/python2.6/site-packages/M2Crypto/httpslib.py", line 50, in connect
    self.sock.connect((self.host, self.port))
  File "/usr/lib64/python2.6/site-packages/M2Crypto/SSL/Connection.py", line 181, in connect
    self.socket.connect(addr)
  File "<string>", line 1, in connect
error: [Errno 110] Connection timed out