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/etcdclient.go b/pkg/db/kvstore/etcdclient.go
index 0165e18..aa5adbf 100644
--- a/pkg/db/kvstore/etcdclient.go
+++ b/pkg/db/kvstore/etcdclient.go
@@ -22,7 +22,7 @@
 	"sync"
 	"time"
 
-	"github.com/opencord/voltha-lib-go/v3/pkg/log"
+	"github.com/opencord/voltha-lib-go/v4/pkg/log"
 	v3Client "go.etcd.io/etcd/clientv3"
 	v3Concurrency "go.etcd.io/etcd/clientv3/concurrency"
 	v3rpcTypes "go.etcd.io/etcd/etcdserver/api/v3rpc/rpctypes"