§ 123. Restrictions on official referees. No official referee continued in office and serving under this article, as amended, shall during his continuance in office, other than as member of a constitutional convention, or the incumbent of a non-salaried office in the educational system of the state hold any other public office or trust, elective or appointive, practice law, act as attorney or counsellor in any court of this state, or act as receiver or commissioner, or unofficial referee in any court, but shall devote his whole time and capacity to the duties of his office as such official referee.