[gnome-tetravex] Replace deprecated method.

[Arnaud B. <arnaudb src gnome org>]

commit c880d806e19d980143e08aca79bc441ddcec779d
Author: Arnaud Bonatti <arnaud bonatti gmail com>
Date:   Fri Feb 14 06:38:55 2020 +0100

    Replace deprecated method.
    
    Bump accordingly Gtk+ required version to 3.22.

 meson.build             | 2 +-
 src/gnome-tetravex.vala | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/meson.build b/meson.build
index e134bf4..f6ca530 100644
--- a/meson.build
+++ b/meson.build
@@ -27,7 +27,7 @@ bindir      = join_paths (get_option ('prefix'), get_option ('bindir'))
 gio_dep     = dependency ('gio-2.0',    version: '>= 2.42.0')
 glib_dep    = dependency ('glib-2.0',   version: '>= 2.42.0')
 if get_option('build_gui')
-  gtk_dep   = dependency ('gtk+-3.0',   version: '>= 3.14')
+  gtk_dep   = dependency ('gtk+-3.0',   version: '>= 3.22.0')
 endif
 # TODO build requires vala 0.46.3 for GLib vapi
 
diff --git a/src/gnome-tetravex.vala b/src/gnome-tetravex.vala
index 62ec272..100a6b1 100644
--- a/src/gnome-tetravex.vala
+++ b/src/gnome-tetravex.vala
@@ -980,7 +980,7 @@ private class Tetravex : Gtk.Application
     {
         try
         {
-            show_uri (window.get_screen (), "help:gnome-tetravex", get_current_event_time ());
+            show_uri_on_window (window, "help:gnome-tetravex", get_current_event_time ());
         }
         catch (Error e)
         {