TBR: syncbase: fix compilation error

Change-Id: I38a81b4756b11e71abfc0c7b8a42676a5445cab8
diff --git a/x/ref/services/syncbase/vsync/responder.go b/x/ref/services/syncbase/vsync/responder.go
index 8ba9cd9..80c2c52 100644
--- a/x/ref/services/syncbase/vsync/responder.go
+++ b/x/ref/services/syncbase/vsync/responder.go
@@ -178,7 +178,7 @@
 		return
 	}
 
-	err := store.RunInTransaction(rSt.st, func(tx store.StoreReadWriter) error {
+	err := store.RunInTransaction(rSt.st, func(tx store.Transaction) error {
 		sg, err := getSyncGroupById(ctx, tx, gid)
 		if err != nil {
 			return err