[vala/0.50] gtk4: Update to 4.0.2

[Rico Tzschichholz <ricotz src gnome org>]

commit 74e502f82353d53271c753d173c610484391668e
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Wed Jan 20 09:42:32 2021 +0100

    gtk4: Update to 4.0.2

 vapi/gtk4.vapi | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/vapi/gtk4.vapi b/vapi/gtk4.vapi
index 8c8ecb53e..ceb18df96 100644
--- a/vapi/gtk4.vapi
+++ b/vapi/gtk4.vapi
@@ -5382,6 +5382,7 @@ namespace Gdk {
                public Gdk.FrameClock frame_clock { get; construct; }
                public int height { get; }
                public bool mapped { get; }
+               public int scale_factor { get; }
                public int width { get; }
                public signal void enter_monitor (Gdk.Monitor monitor);
                public signal bool event (Gdk.Event event);
@@ -14055,7 +14056,7 @@ namespace Gtk {
        [CCode (cheader_filename = "gtk/gtk.h", instance_pos = 2.9)]
        public delegate string ScaleFormatValueFunc (Gtk.Scale scale, double value);
        [CCode (cheader_filename = "gtk/gtk.h", instance_pos = 2.9)]
-       public delegate bool ShortcutFunc (Gtk.Widget widget, GLib.Variant args);
+       public delegate bool ShortcutFunc (Gtk.Widget widget, GLib.Variant? args);
        [CCode (cheader_filename = "gtk/gtk.h", instance_pos = 1.9)]
        public delegate bool TextCharPredicate (unichar ch);
        [CCode (cheader_filename = "gtk/gtk.h", instance_pos = 1.9)]