[gimp] app: fix a warning.

[Jehan <jehanp src gnome org>]

commit 9e9e6f0e9ac935464b3a97eac22ef89ec280b192
Author: Jehan <jehan girinstud io>
Date:   Tue Aug 13 20:43:39 2019 +0200

    app: fix a warning.

 app/display/gimptoolgui.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/app/display/gimptoolgui.c b/app/display/gimptoolgui.c
index 2ef01664e8..2400ab3ba5 100644
--- a/app/display/gimptoolgui.c
+++ b/app/display/gimptoolgui.c
@@ -899,8 +899,8 @@ gimp_tool_gui_update_buttons (GimpToolGui *gui)
         }
       else
         {
-          gimp_dialog_set_alternative_button_order_from_array (GTK_DIALOG (private->dialog),
-                                                              n_ids, ids);
+          gimp_dialog_set_alternative_button_order_from_array (GIMP_DIALOG (private->dialog),
+                                                               n_ids, ids);
         }
     }