[gimp] app: don't leak curve in gimp_curves_config_save_cruft()

[Ell <ell src gnome org>]

commit eda8b717d5e94c6ee4879495a87db138c7b40832
Author: Ell <ell_se yahoo com>
Date:   Fri Apr 19 15:27:30 2019 -0400

    app: don't leak curve in gimp_curves_config_save_cruft()

 app/operations/gimpcurvesconfig.c | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/app/operations/gimpcurvesconfig.c b/app/operations/gimpcurvesconfig.c
index 0bac4abf52..52ebad9939 100644
--- a/app/operations/gimpcurvesconfig.c
+++ b/app/operations/gimpcurvesconfig.c
@@ -690,6 +690,8 @@ gimp_curves_config_save_cruft (GimpCurvesConfig  *config,
         }
 
       g_string_append_printf (string, "\n");
+
+      g_object_unref (curve);
     }
 
   if (! g_output_stream_write_all (output, string->str, string->len,