[gimp/gtk3-port] app: do not run gtk_window_present() in about_dialog_create().

[Jehan Pagès <jehanp src gnome org>]

commit dd8a15865d52c9d6b02f73424c0bee4b8af5c3fc
Author: Jehan <jehan girinstud io>
Date:   Thu May 3 03:51:28 2018 +0200

    app: do not run gtk_window_present() in about_dialog_create().
    
    The window will be raised soon after anyway. No need to do it too early,
    which makes setting a transient parent useless afterwards. In particular
    we were still getting a "GtkDialog mapped without a transient parent"
    message.

 app/dialogs/about-dialog.c |    2 --
 1 files changed, 0 insertions(+), 2 deletions(-)
---
diff --git a/app/dialogs/about-dialog.c b/app/dialogs/about-dialog.c
index 3f1eac7..4822512 100644
--- a/app/dialogs/about-dialog.c
+++ b/app/dialogs/about-dialog.c
@@ -167,8 +167,6 @@ about_dialog_create (GimpContext *context)
       g_list_free (children);
     }
 
-  gtk_window_present (GTK_WINDOW (dialog.dialog));
-
   return dialog.dialog;
 }