fix loadbalancer issue in UMap

this may need a more elaborate fix later, but it works for now. The
problem was that the apxCPU of UMaps was never added, but it was
removed at synth release, resulting in negative load information and
all events targeting one server after a while.
fix startPos for point_circle UMap

this caused strange behaviour for > 15s start pos, perhaps a roundoff
error.