invalid failure to load .net.xml and additionals from options

[namdre]

when loading net.xml and additionals at the same time via options, the network geometry has not been computed while the additionals are validated.
In this state, edge lengths are approximated by the distance between junctions. For strongly curved edges this can introduce major errors and lead to the reject of additionals placed near the end of the edge (since the edge seems to be too short).