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

[Michael Schumacher <schumaml src gnome org>]

commit ae90edd3c31c2eb23352a72de4577b5660151c20
Author: Michael Schumacher <schumaml gmx net>
Date:   Thu Jul 5 11:52:20 2018 +0000

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

 tests/mipmap/rotate.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/tests/mipmap/rotate.sh b/tests/mipmap/rotate.sh
index ceed5f174..5a038b40c 100755
--- a/tests/mipmap/rotate.sh
+++ b/tests/mipmap/rotate.sh
@@ -8,7 +8,7 @@ if [ ! -f $abs_top_builddir/bin/gegl ]; then
   echo "Skipping test-rotate due to lack of gegl executable"
   exit 77
 else
-  GEGL_TILE_SIZE=8x8 GEGL_PATH=$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-output.png           \
           -- rotate degrees=10.0  \