Cannot deploy MultiClusterHub when `Separate Certificate Management` is enabled

Issue

• When attempting to deploy the MultiClusterHub, if the user selects the option to Separate Certificate Management from the Edit Form page on MultiClusterHub creation, the MultiClusterHub custom resource will stay in an Unknown state not progressing past the creation of the multiclusterhub-repo pod.

Additionally, when attempting to delete the MultiClusterHub, the deletion fails and the UI returns an error:

admission webhook "multiclusterhub.validating-webhook.open-cluster-management.io" denied the request: Error retrieving ManagedClusters`

Looking at the multiclusterhub-operator pod logs we can see that the deployment of the MultiClusterHub is pending a secret in the cert-manager namespace which does not exist.

{"level":"error","ts":1599056839.7014687,"logger":"controller_multiclusterhub","msg":"Failed to create secret","Copying Secret to cert-manager namespace":"quay-secret","Namespace.Name":"cert-manager","error":"namespaces \"cert-manager\" not found","stacktrace":"github.com/go-logr/zapr.(*zapLogger).Error\n\t/remote-source/deps/gomod/pkg/mod/github.com/go-logr/zapr@v0.1.1/zapr.go: