[mutter] startup-notification: Silence warning

[Carlos Garnacho <carlosg src gnome org>]

commit ff507273d2b991260ab84fc091dc9954ef61075c
Author: Jonas Ådahl <jadahl gmail com>
Date:   Fri Jan 18 18:18:57 2019 +0100

    startup-notification: Silence warning
    
    Warning in question:
    
    ../src/core/startup-notification.c:646:16: error: unused variable ‘display’ [-Werror=unused-variable]

 src/core/startup-notification.c | 2 --
 1 file changed, 2 deletions(-)
---
diff --git a/src/core/startup-notification.c b/src/core/startup-notification.c
index 546891065..6319eb1ca 100644
--- a/src/core/startup-notification.c
+++ b/src/core/startup-notification.c
@@ -643,8 +643,6 @@ meta_startup_notification_get_sequences (MetaStartupNotification *sn)
 MetaLaunchContext *
 meta_startup_notification_create_launcher (MetaStartupNotification *sn)
 {
-  MetaDisplay *display = sn->display;
-
   return g_object_new (META_TYPE_LAUNCH_CONTEXT,
                        "display", sn->display,
                        NULL);