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

Change-Id: I32074b5c05b08f8ebd2205f8dc2af225bff465cc
diff --git a/rw_core/core/device/agent_image.go b/rw_core/core/device/agent_image.go
index daae220..f63faa2 100644
--- a/rw_core/core/device/agent_image.go
+++ b/rw_core/core/device/agent_image.go
@@ -21,8 +21,8 @@
 
 	"github.com/gogo/protobuf/proto"
 	"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"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
 )