test/helpers: Disable NodePort health checks if using kube-proxy
test/helpers: Disable NodePort health checks if using kube-proxy

In the 4.19 CI job, we run with KPR=strict for most tests even though
kube-proxy is installed. As a result, we get an error message because
the agent fails to listen on the health checks port. In that setup, we
should instead disable health checks.

Signed-off-by: Paul Chaignon <a027184a55211cd23e3f3094f1fdc728df5e0500@cilium.io>

cilium/cilium,cilium/cilium,michi-covalent/cilium,tklauser/cilium,tklauser/cilium,tklauser/cilium,tklauser/cilium,michi-covalent/cilium,cilium/cilium,cilium/cilium,michi-covalent/cilium,michi-covalent/cilium,cilium/cilium,tklauser/cilium,michi-covalent/cilium