[gtk-web/issue-37] Fix C sample code

[Emmanuele Bassi <ebassi src gnome org>]

commit cdae910a2b1f5f586db45d2b5461fb02ddd67656
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Thu Mar 5 12:53:53 2020 +0000

    Fix C sample code
    
    Missing the instance argument.
    
    Fixes: #37

 _data/sample_codes.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/_data/sample_codes.yml b/_data/sample_codes.yml
index d19cf8a..594bbe5 100644
--- a/_data/sample_codes.yml
+++ b/_data/sample_codes.yml
@@ -131,6 +131,6 @@ codes:
         GtkApplication *app = gtk_application_new ("com.example.GtkApplication",
                                                    G_APPLICATION_FLAGS_NONE);
         g_signal_connect (app, "activate", G_CALLBACK (on_activate), NULL);
-        return g_application_run (argc, argv);
+        return g_application_run (G_APPLICATION (app), argc, argv);
       }
       ```