[gegl] tests/compositions: replace contrast-curve image reference

[Thomas Manni <tmanni src gnome org>]

commit ef3fb325ce4647115328d0ddafdf0827168f71e6
Author: Thomas Manni <thomas manni free fr>
Date:   Tue Mar 3 21:25:37 2015 +0100

    tests/compositions: replace contrast-curve image reference

 tests/compositions/reference/contrast-curve.png |  Bin 281055 -> 265335 bytes
 1 files changed, 0 insertions(+), 0 deletions(-)
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diff --git a/tests/compositions/reference/contrast-curve.png b/tests/compositions/reference/contrast-curve.png
index 27d3098..c23a6bc 100644
Binary files a/tests/compositions/reference/contrast-curve.png and 
b/tests/compositions/reference/contrast-curve.png differ