Forgot some error checking.

client/fingerprint/network_unix.go

@@ -154,7 +154,11 @@ func (f *NetworkFingerprint) nativeIpAddress(device string) (string, error) {
 	// TODO: should we handle IPv6 here? How do we determine precedence?
 	for _, i := range ifaces {
 		if i.Name == device {
-			addrs, _ := i.Addrs()
+			addrs, err := i.Addrs()
+			if err != nil {
+				return "", errors.New("could not retrieve interface IP addresses")
+			}
+
 			for _, a := range addrs {
 				switch v := a.(type) {
 				case *net.IPNet: