[seed] seed_exception_to_string: don't leak the stack msg

[Alan Knowles <alank src gnome org>]

commit c4c4fcf762a461c23b55e9da1ffc743285b50e4c
Author: Emilio Pozuelo Monfort <emilio pozuelo collabora co uk>
Date:   Wed Jun 12 11:13:36 2013 +0200

    seed_exception_to_string: don't leak the stack msg
    
    https://bugzilla.gnome.org/show_bug.cgi?id=702081

 libseed/seed-exceptions.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/libseed/seed-exceptions.c b/libseed/seed-exceptions.c
index abaa210..ed37054 100644
--- a/libseed/seed-exceptions.c
+++ b/libseed/seed-exceptions.c
@@ -261,6 +261,7 @@ seed_exception_to_string (JSContextRef ctx, JSValueRef e)
   g_free (mes);
   g_free (file);
   g_free (name);
+  g_free (stack);
 
   return ret;
 }