VOL-3589 Update voltha go to support new version v4 of voltha protos

Change-Id: I32074b5c05b08f8ebd2205f8dc2af225bff465cc
diff --git a/rw_core/core/adapter/agent.go b/rw_core/core/adapter/agent.go
index 7189cff..f8ec23c 100644
--- a/rw_core/core/adapter/agent.go
+++ b/rw_core/core/adapter/agent.go
@@ -19,8 +19,8 @@
 import (
 	"context"
 	"github.com/golang/protobuf/ptypes"
-	"github.com/opencord/voltha-lib-go/v3/pkg/log"
-	"github.com/opencord/voltha-protos/v3/go/voltha"
+	"github.com/opencord/voltha-lib-go/v4/pkg/log"
+	"github.com/opencord/voltha-protos/v4/go/voltha"
 	"sync"
 	"time"
 )