Fix nil-pointer dereference in sciond.Path.String (#3519)
Fix nil-pointer dereference in sciond.Path.String (#3519)

A sciond.Path with a nil-overlay could not be printed.
Fixed by using UDPAddr.String instead of manually formatting IP:port.
Oncilla/scion,netsec-ethz/scion,netsec-ethz/scion,Oncilla/scion,netsec-ethz/scion,Oncilla/scion,Oncilla/scion,netsec-ethz/scion