[gegl] tests: use GEGL_THREADS=1 to check if this fixes the mipmap rotate output

[Michael Schumacher <schumaml src gnome org>]

commit 7a44050f0497737faa4959ad85fc6d90e8369703
Author: Michael Schumacher <schumaml gmx net>
Date:   Thu Jul 5 11:44:50 2018 +0000

    tests: use GEGL_THREADS=1 to check if this fixes the mipmap rotate output

 tests/mipmap/rotate-crop.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/tests/mipmap/rotate-crop.sh b/tests/mipmap/rotate-crop.sh
index 06338f12d..16519e93b 100755
--- a/tests/mipmap/rotate-crop.sh
+++ b/tests/mipmap/rotate-crop.sh
@@ -8,7 +8,7 @@ if [ ! -f $abs_top_builddir/bin/gegl ]; then
   echo "Skipping test-rotate-crop due to lack of gegl executable"
   exit 77
 else
-  GEGL_TILE_SIZE=8x8 GEGL_PATH=$abs_top_builddir/operations GEGL_USE_OPENCL=no GEGL_MIPMAP_RENDERING=1 
$abs_top_builddir/bin/gegl                                       \
+  GEGL_TILE_SIZE=8x8 GEGL_PATH=$abs_top_builddir/operations GEGL_USE_OPENCL=no GEGL_MIPMAP_RENDERING=1 
GEGL_THREADS=1 $abs_top_builddir/bin/gegl                                       \
           -s 0.33 $abs_top_srcdir/tests/compositions/data/car-stack.png -o      \
           $abs_top_builddir/tests/mipmap/rotate-crop-output.png           \
           -- rotate degrees=15.0 crop x=147 y=66 width=200 height=200 \