[gnome-calendar] window: Silence a compilar warning

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 229b6f7add40bce38fbd50affb4d144be6b0506c
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Sun Sep 5 18:07:27 2021 -0300

    window: Silence a compilar warning

 src/gui/gcal-window.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/gui/gcal-window.c b/src/gui/gcal-window.c
index 0057a9fe..5b233530 100644
--- a/src/gui/gcal-window.c
+++ b/src/gui/gcal-window.c
@@ -1222,5 +1222,5 @@ gcal_window_import_files (GcalWindow  *self,
   gtk_window_set_transient_for (GTK_WINDOW (self->import_dialog), GTK_WINDOW (self));
   gtk_window_present (GTK_WINDOW (self->import_dialog));
 
-  g_object_add_weak_pointer (G_OBJECT (self->import_dialog), &self->import_dialog);
+  g_object_add_weak_pointer (G_OBJECT (self->import_dialog), (gpointer *)&self->import_dialog);
 }