message: integration_tests: remove unneeded sleep
  This sleep caused the activity to be wrong if the simulation was sped
  up.
diff: @@ -60,7 +60,6 @@ TEST_F(SitlTest, OffboardPositionNED)
  std::this_thread::sleep_for(std::chrono::milliseconds(50));
  }
  offboard->set_position_ned({0.0f, 0.0f, -10.0f, 90.0f});
  - std::this_thread::sleep_for(std::chrono::seconds(2));
  }
  // Let's make sure that offboard knows it is active.
  