[gimp/gtk3-port: 269/386] app: the "Default" theme had been removed to "System" a long time ago.

[Michael Natterer <mitch src gnome org>]

commit aec8f3e0f24785fd0c6b79d6a74e118cf152f69a
Author: Jehan <jehan girinstud io>
Date:   Tue May 1 05:00:30 2018 +0200

    app: the "Default" theme had been removed to "System" a long time ago.
    
    Fix a "No such file or directory" error.

 app/gui/themes.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/app/gui/themes.c b/app/gui/themes.c
index 82801e4..18cd167 100644
--- a/app/gui/themes.c
+++ b/app/gui/themes.c
@@ -306,7 +306,7 @@ themes_apply_theme (Gimp        *gimp,
       else
         {
           tmp = g_build_filename (gimp_data_directory (),
-                                  "themes", "Default", "gimp.css",
+                                  "themes", "System", "gimp.css",
                                   NULL);
           css_theme = g_file_new_for_path (tmp);
           g_free (tmp);