The existence of HTTP_PROXY should not be the reason to mark a cluster as disconnected.

The HTTP_PROXY is set for the proxy we have running directly on the CI env.
A disconnected cluster is only created when using a bastion-proxy VM and enabling all communication of the openshift cluster through it, in the CI that happens when CONFIG_TYPE=proxy

By marking a cluster as disconnected when running openshift-test we end up skipping a variety of tests.

https://github.com/openshift/release/blob/master/ci-operator/step-registry/openshift/e2e/test/openshift-e2e-test-commands.sh#L157-L158