Will want to remove the workaround docs for upgrading router pods when EnMasse issue #3256 (Create listener on old probe port to fix upgrade) is merged.

Per Keith: "There was a workaround added to io.enmasse.systemtest.isolated.upgrade.UpgradeTest#checkImagesUpdated and documented documentation/modules/proc-upgrading-router-pods.adoc which should be removed if this is fix is successful."