CityLights throws exceptions when applied to nonexistent bodies

[Kerbas-ad-astra]

I was testing on my RSS install and ended up commenting out the cbNameLater = Earth line in Earth's configuration file, so Earth's internal name was still Kerbin and not Earth, which is not how RSSVE is defined. This provoked a flood of exceptions from CityLights.LocalCityComponent.OnPreCull() in the flight scene.