[gegl] gegl:cache: make non-threaded

[N/A <ell src gnome org>]

commit 3a8120d76a91d94dc7c4875adcd4b6b16effbea4
Author: Ell <ell_se yahoo com>
Date:   Sun Jul 2 15:58:39 2017 -0400

    gegl:cache: make non-threaded
    
    Not thread safe, and there's no point in paralellizing it anyway.

 operations/core/cache.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/operations/core/cache.c b/operations/core/cache.c
index f4921b7..e306c5b 100644
--- a/operations/core/cache.c
+++ b/operations/core/cache.c
@@ -83,6 +83,7 @@ gegl_op_class_init (GeglOpClass *klass)
 
   operation_class->no_cache      = FALSE;
   operation_class->want_in_place = FALSE;
+  operation_class->threaded      = FALSE;
   operation_class->prepare       = prepare;
   point_filter_class->process    = process;