Fix confirmation on warningp

[Affonso-Gui]

Apparently we can reproduce the confirmation behavior of the (unused):angle-vector-safe by setting the (even more unused) warningp flag. By doing so, when about to move the real robot a confirmation prompt pops out asking if that is really what we want.

However, when using the warningp this prompt is inverted, so saying that you do NOT want the robot to move make it move:

(send *ri* :warningp t)
(send *ri* :angle-vector (send *pr2* :init-pose) 5000)
Are you sure to move the real robot? (l_arm_controller/follow_joint_trajectory) (YES or NO): no
Are you sure to move the real robot? (r_arm_controller/follow_joint_trajectory) (YES or NO): no
Are you sure to move the real robot? (head_traj_controller/follow_joint_trajectory) (YES or NO): no
Are you sure to move the real robot? (torso_controller/follow_joint_trajectory) (YES or NO): no

;; ROBOT MOVES

[Affonso-Gui]

@k-okada Can I ask for a review?