As detailed in #113, services without a selector, often externalName services, render as being associated with all pods in the cluster. This is returned as well from requests directly to the /api/services endpoint.

The issue appears to be occurring at this point in the api call.

labelsMatchSelectors doesnt have a check for if the selectors parameter is empty, so it never iterates and just returns true for every pod. This MR ensures comparing a selectors map against a map of labels returns false when there were no selectors specified.

Closes #113