virtctl image-upload fails with error: x509: certificate signed by unknown authority

Issue

• When using the virtctl command-line tool to upload a diskvolume image to a cluster, a user may experience an error message and upload failure if the certificate is untrusted by the system executing the virtctl command.

# virtctl image-upload dv template-example-sequence --size=2.4Ti --image-path=vm-example-template.tar.gz
PVC namespace/template-example-sequence not found
DataVolume namespace/template-example-sequence created
Waiting for PVC template-example-sequence upload pod to be ready...
Pod now ready
Uploading data to https://test-openshift.apps.example.com

 0 B / 123.45 GiB [--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------]   0.00% 0s

Post "https://test-openshift.apps.example.com/v1alpha1/upload": x509: certificate signed by unknown authority