Avoid an option modification that causes bug in search.plt

rosenbrock.plt

@@ -60,11 +60,13 @@ test(cosinus_integration, [setup(command(clear_model)), cleanup(command(clear_mo
   check_integration_2(D, 1e-5).
 
 test(test_ball, [setup(command(clear_model)), cleanup(command(clear_model))]) :-
+  get_option(time, Time_default),
   command(load("library/examples/RobustMonitoring/ball.bc")),
   command(option(maximum_step_size:1e-2)),
   command(numerical_simulation(method:rsbk)),
   get_table_data(D),
-  check_integration_ball(D, 1e-3).
+  check_integration_ball(D, 1e-3),
+  set_option(time, Time_default).
 
 test(test_time_event, [setup(command(clear_model)), cleanup(command(clear_model))]) :-
   command(k*a for a => b),