§ 4.   Civil and military officers. All officers, civil and military, now holding their offices and appointments in this territory under the authority of the United States, or under the authority of the territory of Dakota, shall continue to hold and exercise their respective offices and appointments until superseded under this Constitution: provided, that the provisions of the above sections shall be subject to the provisions of the act of Congress providing for the admission of the state of South Dakota, approved by the president of the United States on February 22, 1889.