[gnome-clocks] timer-face: Return a bool value from grab_focus()

[Bilal Elmoussaoui <bilelmoussaoui src gnome org>]

commit ca538eae697d1be9a12c4c354231692f27c0d513
Author: Yetizone <andreii lisita gmail com>
Date:   Fri Jan 15 20:27:42 2021 +0200

    timer-face: Return a bool value from grab_focus()
    
    In GTK4 the grab_focus() virtual function must return a bool value
    https://valadoc.org/gtk4/Gtk.Widget.grab_focus.html

 src/timer-face.vala | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
---
diff --git a/src/timer-face.vala b/src/timer-face.vala
index 5cad12f1..0cba646a 100644
--- a/src/timer-face.vala
+++ b/src/timer-face.vala
@@ -134,10 +134,13 @@ public class Face : Gtk.Stack, Clocks.Clock {
         bell.ring_once ();
     }
 
-    public override void grab_focus () {
+    public override bool grab_focus () {
         if (timers.get_n_items () == 0) {
             start_button.grab_focus ();
+            return true;
         }
+
+        return false;
     }
 }