Fix/k8s listener

[flashvoid]

So, @debedb. I've figured out why kubernetes listener service wasn't working. There were 2 reasons really:

• you missed nsUrl from original code and tried to use urlPrefix instead - I've fixed that
• you missed for {} loop in main.go - that's why service used to exit after the first run What need to happen now:
• could you please fix tests for kubernetes_listener so they would take in account nsUrl.