[gnote] Replace deprecated set_margin_left with set_margin_start

[Aurimas Černius <aurimasc src gnome org>]

commit a953eb3394a3a51456ed5b9cd347b8d1b2fc9dd2
Author: Aurimas Černius <aurisc4 gmail com>
Date:   Sun May 9 21:23:35 2021 +0300

    Replace deprecated set_margin_left with set_margin_start

 src/utils.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/utils.cpp b/src/utils.cpp
index 3ac7366b..a6927cf8 100644
--- a/src/utils.cpp
+++ b/src/utils.cpp
@@ -353,7 +353,7 @@ namespace gnote {
       
       m_extra_widget_vbox = manage(new Gtk::Grid);
       m_extra_widget_vbox->show();
-      m_extra_widget_vbox->set_margin_left(12);
+      m_extra_widget_vbox->set_margin_start(12);
       label_vbox->attach(*m_extra_widget_vbox, 0, label_vbox_row++, 1, 1);
 
       switch (btn_type) {