Sometimes tethers drop too near the end of a light arc

[TheCraiggers]

At times, tethers will drop so close to the end of a flight arc, the tether will be inside its parent object. This does not affect gameplay, but looks ugly.

Should probably rewrite it so that tethers don't spawn at their parent's location, but a little further back. This also means tethers have to wait just a bit longer before spawning.