[gnome-clocks] timer-face: Adapt to Gtk.Box API changes

[Bilal Elmoussaoui <bilelmoussaoui src gnome org>]

commit 9ae6fb0ccac0f565fed2b695266cdfb9596e50ad
Author: Yetizone <andreii lisita gmail com>
Date:   Sun Feb 14 17:14:24 2021 +0200

    timer-face: Adapt to Gtk.Box API changes

 src/timer-face.vala | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/timer-face.vala b/src/timer-face.vala
index 0cba646a..6de94e46 100644
--- a/src/timer-face.vala
+++ b/src/timer-face.vala
@@ -76,8 +76,8 @@ public class Face : Gtk.Stack, Clocks.Clock {
         notification.set_body (_("Timer countdown finished"));
         notification.set_priority (HIGH);
 
-        no_timer_container.add (timer_setup);
-        no_timer_container.reorder_child (timer_setup, 1);
+        var no_timer_container_first_child = no_timer_container.get_first_child ();
+        no_timer_container.insert_child_after (timer_setup, no_timer_container_first_child);
         set_visible_child_name ("empty");
 
         start_button.set_sensitive (false);