bin/scion: fix regression when finding local ip
When using `scion sp` in HEAD versus older versions, this
error was happening:
```
host# scion sp 1-ff00:0:110 --refresh
Error: failed to determine local IP
no entry found svc="CS A (0x0002)" services="map[]"
```
@@ -54,7 +54,7 @@ func ServiceTypeFromString(s string) ServiceType {
switch strings.ToLower(s) {
case "router":
return Router
- case "control":
+ case "control", "cs":
return Control
case "discovery":
return Discovery
