[freeflow] Make tests pass again

test/freeflow/rans/CMakeLists.txt

@@ -7,7 +7,7 @@ dune_add_test(NAME test_pipe_laufer_zeroeq
               COMMAND ${CMAKE_SOURCE_DIR}/bin/testing/runtest.py
               CMD_ARGS  --script fuzzy
                         --files ${CMAKE_SOURCE_DIR}/test/references/pipe_laufer_zeroeq.vtu
-                                ${CMAKE_CURRENT_BINARY_DIR}/pipe_laufer_zeroeq_reference-00018.vtu
+                                ${CMAKE_CURRENT_BINARY_DIR}/pipe_laufer_zeroeq_reference-00016.vtu
                         --command "${CMAKE_CURRENT_BINARY_DIR}/test_pipe_laufer_zeroeq test_pipe_laufer_reference.input")
 
 dune_add_test(NAME test_pipe_zeroeqni