add default options again (required in MPI test)

examples/tree_2d_dgsem/elixir_advection_extended.jl

@@ -78,7 +78,8 @@ callbacks = CallbackSet(summary_callback,
 alg = CarpenterKennedy2N54(williamson_condition = false)
 sol = solve(ode, alg,
             dt = 1.0, # solve needs some value here but it will be overwritten by the stepsize_callback
-            save_everystep = false, callback = callbacks);
+            callback = callbacks;
+            ode_default_options()...); # default options because an adaptive time stepping method is used in test_mpi_tree.jl
 
 # Print the timer summary
 summary_callback()