But no court, under the provisions of this chapter, shall in any other matter have power to inquire into the legality or justice of any process, judgment, decree or order of any court legally constituted, nor into the justice or propriety of any commitment for contempt, made by any court, officer or body, according to law, and plainly charged in such commitment, as herein provided; but nothing in this section contained, nor any other part of this chapter, shall be so construed as to prevent any prisoner from being discharged when the matter alleged in the order of commitment shall not, in point of law, amount to a contempt.