Use new router option in 1.5 to bind ports only when ready

Cf. https://github.com/openshift/origin/commit/7b3e0d3b

This would resolve the issue that when the HAProxy router starts, it initially has no route information and returns 503. Only a few seconds later does it reload with actual route data.

In our case with DNSLB it seems preferable to only bind ports when route information has been loaded.

Another good thing with this is that the stats port is still started immediately, so the pod will be 'ready' and have its IP listed in the router endpoints, in turn making it available for peers section configuration (without it we have the error Proxy 'ip_affinity_gitlab-registry_registry': unable to find local peer 'router-15-wmvx1' in peers section 'openshift_peers'). The error will still show up when HAProxy starts initially, but will hopefully be gone by the time it reloads the final configuration (however this is not guaranteed, as nothing actually waits for the current HAPRoxy pod to be ready before it is told to bind ports - we're only waiting for route information to be loaded)