[gnome-builder/wip/gtk4-port] plugins/meson-templates: fix parent type for AdwApplication

[Christian Hergert <chergert src gnome org>]

commit 1a1c7aac1779e8c2d37fae5f0112925d5db1e831
Author: Christian Hergert <chergert redhat com>
Date:   Tue Jun 7 17:07:25 2022 -0700

    plugins/meson-templates: fix parent type for AdwApplication

 src/plugins/meson-templates/resources/src/application.c | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/src/plugins/meson-templates/resources/src/application.c 
b/src/plugins/meson-templates/resources/src/application.c
index 536d1e6d7..c327dfc8c 100644
--- a/src/plugins/meson-templates/resources/src/application.c
+++ b/src/plugins/meson-templates/resources/src/application.c
@@ -5,7 +5,11 @@
 
 struct _{{PreFix}}Application
 {
+{{if is_adwaita}}
+  AdwApplication parent_instance;
+{{else}}
   GtkApplication parent_instance;
+{{end}}
 };
 
 G_DEFINE_TYPE ({{PreFix}}Application, {{prefix_}}_application, {{if 
is_adwaita}}ADW_TYPE_APPLICATION{{else}}GTK_TYPE_APPLICATION{{end}})