Extended.[networking] services when using a plugin that isolates namespaces by default should prevent connections to pods in different namespaces on the same node via service IPs

[mfojtik]

Seen here: https://ci.openshift.redhat.com/jenkins/job/merge_pull_request_origin/689/testReport/junit/(root)/Extended/_networking__services_when_using_a_plugin_that_isolates_namespaces_by_default_should_prevent_connections_to_pods_in_different_namespaces_on_the_same_node_via_service_IPs/

logs:

/data/src/github.com/openshift/origin/_output/local/go/src/github.com/openshift/origin/test/extended/networking/services.go:42
Expected error:
    <*errors.errorString | 0xc421c00a10>: {
        s: "Failed to get endpoints for e2e-tests-net-services1-jk963/service-mf46q",
    }
    Failed to get endpoints for e2e-tests-net-services1-jk963/service-mf46q
not to have occurred
/data/src/github.com/openshift/origin/_output/local/go/src/github.com/openshift/origin/test/extended/networking/util.go:147

[danwinship]

dup of #14197