[gegl] tests: commit updated posterize.xml

[Øyvind "pippin" Kolås <ok src gnome org>]

commit 41accb065ae130f1964fdd5e0f736f1c4175453e
Author: Øyvind Kolås <pippin gimp org>
Date:   Thu Jul 5 22:06:33 2018 +0200

    tests: commit updated posterize.xml

 tests/compositions/posterize.xml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/tests/compositions/posterize.xml b/tests/compositions/posterize.xml
index ec6e7a8b8..36aaa2ba2 100644
--- a/tests/compositions/posterize.xml
+++ b/tests/compositions/posterize.xml
@@ -2,7 +2,7 @@
 <gegl>
   <node operation='gegl:posterize'>
     <params>
-      <param name='levels'>8</param>
+      <param name='levels'>2</param>
     </params>
   </node>
   <node operation='gegl:load'>