[gnome-builder] create-project: fix warning in release mode

[Christian Hergert <chergert src gnome org>]

commit fd70e96e3be47fba145288524fea102bebfe1c9a
Author: Christian Hergert <chergert redhat com>
Date:   Tue Mar 5 16:06:22 2019 -0800

    create-project: fix warning in release mode

 src/plugins/create-project/gbp-create-project-application-addin.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
---
diff --git a/src/plugins/create-project/gbp-create-project-application-addin.c 
b/src/plugins/create-project/gbp-create-project-application-addin.c
index d8d37d141..a38c5c8c2 100644
--- a/src/plugins/create-project/gbp-create-project-application-addin.c
+++ b/src/plugins/create-project/gbp-create-project-application-addin.c
@@ -91,12 +91,11 @@ create_project_cb (GSimpleAction *action,
                    GVariant      *param,
                    gpointer       user_data)
 {
-  GbpCreateProjectApplicationAddin *self = user_data;
   g_autoptr(IdeWorkbench) workbench = NULL;
   IdeGreeterWorkspace *workspace;
 
   g_assert (IDE_IS_MAIN_THREAD ());
-  g_assert (IDE_IS_APPLICATION_ADDIN (self));
+  g_assert (IDE_IS_APPLICATION_ADDIN (user_data));
 
   workbench = ide_workbench_new ();
   ide_application_add_workbench (IDE_APPLICATION_DEFAULT, workbench);