insights registration fails with error CERTIFICATE_VERIFY_FAILED

Issue

• Insights-client --register fails with below error on the client registered to satellite:-

  Conf message: {
    "error": {"message":"Internal Server Error: the server was unable to finish the request. This may be caused by unavailability of some required service, incorrect API call or a server-side bug. There may be more information in the server's logs."}
  }
  

• Below error can be seen in satellite's /var/log/insights-client/insights-client.log:-

  2023-04-03 11:27:29,785    DEBUG insights.client.connection CONF Proxy: http://proxy.example.com:8080
  2023-04-03 11:27:29,835  NETWORK insights.client.connection GET https://cert-api.access.redhat.com/r/insights
  2023-04-03 11:27:29,955  NETWORK insights.client.connection GET https://cert-api.access.redhat.com/r/insights/platform/module-update-router/v1/channel?module=insights-core
  2023-04-03 11:27:30,514    ERROR insights.client.phase.v1 Fatal error
  Traceback (most recent call last):
    File "/etc/insights-client/rpm.egg/insights/client/phase/v1.py", line 32, in _f
      func(client, config)
    File "/etc/insights-client/rpm.egg/insights/client/phase/v1.py", line 129, in update
      client.update()
    File "/etc/insights-client/rpm.egg/insights/client/__init__.py", line 258, in update
      egg_paths = self.fetch()
    File "/etc/insights-client/rpm.egg/insights/client/__init__.py", line 130, in fetch
      egg_release = self.get_egg_url()
    File "/etc/insights-client/rpm.egg/insights/client/__init__.py", line 72, in _init_connection
      return func(self, *args, **kwargs)
    File "/etc/insights-client/rpm.egg/insights/client/__init__.py", line 108, in get_egg_url
      response = self.connection.get(url)
    File "/etc/insights-client/rpm.egg/insights/client/connection.py", line 195, in get
      return self._http_request(url, 'GET', **kwargs)
    File "/etc/insights-client/rpm.egg/insights/client/connection.py", line 189, in _http_request
      res = self.session.request(url=url, method=method, timeout=self.config.http_timeout, **kwargs)
    File "/usr/lib/python2.7/site-packages/requests/sessions.py", line 486, in request
      resp = self.send(prep, **send_kwargs)
    File "/usr/lib/python2.7/site-packages/requests/sessions.py", line 598, in send
      r = adapter.send(request, **kwargs)
    File "/usr/lib/python2.7/site-packages/requests/adapters.py", line 431, in send
      raise SSLError(e, request=request)
  SSLError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:618)