[VOL-2364] handle sub-sequent onuDiscoveryIndication

If ChildDeviceDetected times out then the device never receives the
"enable" call. With this patch we are allowing the device to send a new
discovery indication to retry the process (the OpenOlt agent keeps
sending discovery until an "enable" call is received for that device)

Change-Id: I6a2f5d5e9b0a001361bdca1feb14ca22cf092138
diff --git a/go.mod b/go.mod
index 23d18c7..871f6a2 100644
--- a/go.mod
+++ b/go.mod
@@ -7,7 +7,7 @@
 	github.com/cenkalti/backoff/v3 v3.1.1
 	github.com/gogo/protobuf v1.3.1
 	github.com/golang/protobuf v1.3.2
-	github.com/opencord/voltha-lib-go/v3 v3.0.6
+	github.com/opencord/voltha-lib-go/v3 v3.0.8
 	github.com/opencord/voltha-protos/v3 v3.2.2
 	go.etcd.io/etcd v0.0.0-20190930204107-236ac2a90522
 	google.golang.org/grpc v1.25.1