[gnome-builder] meson-templates: set modal property for about dialog

[Günther Wagner <gwagner src gnome org>]

commit 2503114ba78ce82aacd7dea0bb3ddf88b3e03af5
Author: oscfdezdz <oscfdezdz tuta io>
Date:   Sun Feb 13 20:38:42 2022 +0100

    meson-templates: set modal property for about dialog
    
    Adds this common behavior for about dialogs across GNOME apps to Python GTK4 template.

 src/plugins/meson-templates/resources/src/window-gtk4.py | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/src/plugins/meson-templates/resources/src/window-gtk4.py 
b/src/plugins/meson-templates/resources/src/window-gtk4.py
index 5ec54af63..0ca7c57c2 100644
--- a/src/plugins/meson-templates/resources/src/window-gtk4.py
+++ b/src/plugins/meson-templates/resources/src/window-gtk4.py
@@ -22,4 +22,5 @@ class AboutDialog(Gtk.AboutDialog):
         self.props.authors = ['{{author}}']
         self.props.copyright = '(C) 2021 {{author}}'
         self.props.logo_icon_name = '{{appid}}'
+        self.props.modal = True
         self.set_transient_for(parent)