message: Fix thread_hook unit test
diff: @@ -121,7 +121,7 @@ CAF_TEST(counting_system_without_actor) {
  assumed_init_calls = 1;
  assumed_thread_count = get_or(cfg, "scheduler.max-threads",
  defaults::scheduler::max_threads)
  - + 2; // caf.clock and caf.logger
  + + 1; // caf.clock
  auto& sched = sys.scheduler();
  if (sched.detaches_utility_actors())
  assumed_thread_count += sched.num_utility_actors();
  @@ -131,7 +131,7 @@ CAF_TEST(counting_system_with_actor) {
  assumed_init_calls = 1;
  assumed_thread_count = get_or(cfg, "scheduler.max-threads",
  defaults::scheduler::max_threads)
  - + 3; // caf.clock, caf.logger, and detached actor
  + + 2; // caf.clock and detached actor
  auto& sched = sys.scheduler();
  if (sched.detaches_utility_actors())
  assumed_thread_count += sched.num_utility_actors();
  