Dispatcher can't deliver COLIBRI packets if S=0,C=1

[juagargi]

COLIBRI packets with S=0 and C=1 are created when doing a traceroute with an EER ID, or when using an EER to do a renewal, etc.
These packets cannot be delivered by the current dispatcher, as the host address is picked from the packet SCION header, that contains the destination of the final end-host, and not that of the COLIBRI service.