Update payload function placeholders
Update payload function placeholders

As per https://github.com/TheThingsIndustries/dashboard/issues/90#issuecomment-249515032
TheThingsNetwork/ttn,mgranberry/ttn,TheThingsNetwork/ttn,jvanmalder/ttn,TheThingsNetwork/ttn,jvanmalder/ttn,jvanmalder/ttn,mgranberry/ttn,mgranberry/ttn