Use voltha-protos version 4.0.2
Bump major version of voltha-lib-go to 4.0.0 as this change results
in incompatible API version compared to previous version

Change-Id: I1def58361fb1d85f07d6948ebf1ffb7a92eb0d4c
diff --git a/pkg/db/kvstore/consulclient.go b/pkg/db/kvstore/consulclient.go
index c2cd841..2593608 100644
--- a/pkg/db/kvstore/consulclient.go
+++ b/pkg/db/kvstore/consulclient.go
@@ -19,7 +19,7 @@
 	"bytes"
 	"context"
 	"errors"
-	log "github.com/opencord/voltha-lib-go/v3/pkg/log"
+	log "github.com/opencord/voltha-lib-go/v4/pkg/log"
 	"sync"
 	"time"
 	//log "ciena.com/coordinator/common"