'argocd cluster add' command fails with x509: certificate signed by unknown authority

Issue

• Below error is shown when trying to add a cluster in ArgoCD in Red Hat OpenShift Container Platform.

$ argocd cluster add default/my-cluster:6443/kube:admin
WARNING: This will create a service account `argocd-manager` on the cluster referenced by context `default/my-cluster:6443/kube:admin` with full cluster level admin privileges. Do you want to continue [y/N]? y
INFO[0002] ServiceAccount "argocd-manager" already exists in namespace "kube-system"
INFO[0002] ClusterRole "argocd-manager-role" updated
INFO[0002] ClusterRoleBinding "argocd-manager-role-binding" updated
FATA[0002] rpc error: code = Unknown desc = Get "https://<cluster-api>/version?timeout=32s": x509: certificate signed by unknown authority