[glade] tests: Include back GtkTreeViewColumn

[Alberto Fanjul <albfan src gnome org>]

commit 44b197fd4496752b0503da39b1ca51db3a5c7c03
Author: Victor Toso <me victortoso com>
Date:   Wed Nov 6 11:32:42 2019 +0100

    tests: Include back GtkTreeViewColumn
    
    This was removed in ccb3a8c7dcbd7bd for a release due some criticals
    which are not happening anymore.
    
    Also fixes:
     > ../tests/add-child.c:156:1: warning: ‘assert_column_parented’ defined
     > but not used [-Wunused-function]
     >   156 | assert_column_parented (GObject *parent,
     >       | ^~~~~~~~~~~~~~~~~~~~~~

 tests/add-child.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
---
diff --git a/tests/add-child.c b/tests/add-child.c
index f8c33851..ad12a00c 100644
--- a/tests/add-child.c
+++ b/tests/add-child.c
@@ -295,8 +295,7 @@ main (int   argc,
   add_test (GTK_TYPE_MENU_TOOL_BUTTON, GTK_TYPE_MENU, assert_submenu);
 
   /* Cell layouts */
-  /* FIXME: GtkTreeViewColumn gives a critical when creating it */
-  /* add_test (GTK_TYPE_TREE_VIEW, GTK_TYPE_TREE_VIEW_COLUMN, assert_column_parented); */
+  add_test (GTK_TYPE_TREE_VIEW, GTK_TYPE_TREE_VIEW_COLUMN, assert_column_parented);
   add_child_cells (GTK_TYPE_TREE_VIEW_COLUMN);
   add_child_cells (GTK_TYPE_ICON_VIEW);
   add_child_cells (GTK_TYPE_COMBO_BOX);