Insights client connection test fail with error 'Invalid hostname'

Issue

• Testing connectivity between insights-client and Red Hat network fails with below error:

  # redhat-access-insights --test-connection
  Running Connection Tests...
  Connection test config:
  === Begin Certificate Chain Test ===
  Failed to connect to https://cert-api.access.redhat.com/r/insights. Invalid hostname.
  === End Certificate Chain Test: FAILURE ===
  
  === Begin Upload URL Connection Test ===
  HTTP Status Code: 200
  HTTP Status Text: OK
  HTTP Response Text:
  Successfully connected to: https://cert-api.access.redhat.com/r/insights/uploads/
  === End Upload URL Connection Test: SUCCESS ===
  
  === Begin API URL Connection Test ===
  HTTP Status Code: 200
  HTTP Status Text: OK
  HTTP Response Text: lub-dub
  Successfully connected to: https://cert-api.access.redhat.com/r/insights/
  === End API URL Connection Test: SUCCESS ===
  
  
  Connectivity tests completed with some errors
  See /var/log/insights-client/insights-client.log for more details.