[vala/0.36] gtk+-4.0: Fix TreeView.is_blank_at_pos()

[Rico Tzschichholz <ricotz src gnome org>]

commit ceca0caab28a0af7f9f3fbc368bf1695be3456bb
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Fri Mar 2 15:43:45 2018 +0100

    gtk+-4.0: Fix TreeView.is_blank_at_pos()

 vapi/gtk+-4.0.vapi |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/vapi/gtk+-4.0.vapi b/vapi/gtk+-4.0.vapi
index 1d41f3b..24419a3 100644
--- a/vapi/gtk+-4.0.vapi
+++ b/vapi/gtk+-4.0.vapi
@@ -13937,7 +13937,7 @@ namespace Gtk {
                public int insert_column_with_attributes (int position, string? title, Gtk.CellRenderer cell, 
...);
                public int insert_column_with_data_func (int position, string title, Gtk.CellRenderer cell, 
owned Gtk.TreeCellDataFunc func);
                [Version (since = "3.0")]
-               public bool is_blank_at_pos (int x, int y, out Gtk.TreePath path, out Gtk.TreeViewColumn 
column, out int cell_x, out int cell_y);
+               public bool is_blank_at_pos (int x, int y, out Gtk.TreePath? path, out unowned 
Gtk.TreeViewColumn? column, out int cell_x, out int cell_y);
                [CCode (cname = "gtk_tree_view_row_expanded")]
                public bool is_row_expanded (Gtk.TreePath path);
                [Version (since = "2.12")]