[glom/gtkmm4v4] gtkmm4: Don't use non-existant GtkTreeView::vertical-separator property.

[Murray Cumming <murrayc src gnome org>]

commit fca6e4a80d4881010ad65ac2c4ebe3c453103d51
Author: Murray Cumming <murrayc murrayc com>
Date:   Wed Apr 19 20:57:04 2017 +0200

    gtkmm4: Don't use non-existant GtkTreeView::vertical-separator property.

 glom/mode_data/db_adddel/db_adddel.cc |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/glom/mode_data/db_adddel/db_adddel.cc b/glom/mode_data/db_adddel/db_adddel.cc
index 850769d..9135499 100644
--- a/glom/mode_data/db_adddel/db_adddel.cc
+++ b/glom/mode_data/db_adddel/db_adddel.cc
@@ -544,7 +544,7 @@ guint DbAddDel::get_fixed_cell_height()
   //We get this style property, which might be causing it. murrayc
   //TODO: Find out if this is reallyt the right way to calculate the correct height:
   int extra_height = 0;
-  gtk_widget_style_get(GTK_WIDGET(m_tree_view.gobj()), "vertical-separator", &extra_height, (void*)nullptr);
+  // gtk_widget_style_get(GTK_WIDGET(m_tree_view.gobj()), "vertical-separator", &extra_height, 
(void*)nullptr);
   //std::cout << "debug: extra_height=" << extra_height << std::endl;
 
   return m_fixed_cell_height + extra_height;