[gimp] libgimpthumb: fix "assignment discards ‘ const’ qualifier" warning.

[Jehan Pagès <jehanp src gnome org>]

commit 44fe30ef80ccf09f0f65ec95da83cf63ed7da5c8
Author: Jehan <jehan girinstud io>
Date:   Thu Dec 5 22:18:15 2013 +1300

    libgimpthumb: fix "assignment discards ‘const’ qualifier" warning.

 libgimpthumb/gimp-thumbnail-list.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/libgimpthumb/gimp-thumbnail-list.c b/libgimpthumb/gimp-thumbnail-list.c
index c8dad3f..2086af2 100644
--- a/libgimpthumb/gimp-thumbnail-list.c
+++ b/libgimpthumb/gimp-thumbnail-list.c
@@ -58,7 +58,7 @@ main (gint   argc,
 {
   GOptionContext *context;
   GDir           *dir;
-  gchar          *thumb_folder;
+  const gchar    *thumb_folder;
   const gchar    *folder;
   GError         *error = NULL;