tree data UPDATE add ability to duplicate tree with priv pointers

Signed-off-by: Igor Ryzhov <iryzhov@nfware.com>
diff --git a/src/tree_data.c b/src/tree_data.c
index cc1ad2e..0fdf662 100644
--- a/src/tree_data.c
+++ b/src/tree_data.c
@@ -1738,6 +1738,9 @@
     } else {
         dup->flags = (node->flags & (LYD_DEFAULT | LYD_EXT)) | LYD_NEW;
     }
+    if (options & LYD_DUP_WITH_PRIV) {
+        dup->priv = node->priv;
+    }
     if (trg_ctx == LYD_CTX(node)) {
         dup->schema = node->schema;
     } else {