[gegl] transform: temporarily disable threading

[Øyvind Kolås <ok src gnome org>]

commit b54454fd225c5a807b680dc1be14cba62acfafd7
Author: Øyvind Kolås <pippin gimp org>
Date:   Wed Nov 15 03:58:02 2017 +0100

    transform: temporarily disable threading

 operations/transform/transform-core.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)
---
diff --git a/operations/transform/transform-core.c b/operations/transform/transform-core.c
index 88d82b7..44abed7 100644
--- a/operations/transform/transform-core.c
+++ b/operations/transform/transform-core.c
@@ -168,7 +168,9 @@ op_transform_class_init (OpTransformClass *klass)
   op_class->process                   = gegl_transform_process;
   op_class->prepare                   = gegl_transform_prepare;
   op_class->no_cache                  = TRUE;
-  op_class->threaded                  = TRUE;
+  op_class->threaded                  = FALSE; // XXX : at the moment threading
+                                               // produces right result but
+                                               // slows down most transform - and significantly slows down 
scale
 
   klass->create_matrix = NULL;