[router] Remove old references to errors in router
[router] Remove old references to errors in router

jvanmalder/ttn,jvanmalder/ttn,TheThingsNetwork/ttn,TheThingsNetwork/ttn,TheThingsNetwork/ttn,LoRaWanSoFa/ttn,mgranberry/ttn,mgranberry/ttn,jvanmalder/ttn,mgranberry/ttn,LoRaWanSoFa/ttn