All city elections shall be governed, except as otherwise provided by the Charter, by the laws of the State of Texas governing general and municipal elections, so far as same may be applicable thereto; and in event there shall be any failure of the general laws or this Charter to provide for some feature of the city elections, then the city commission shall have the power to provide for such deficiency, and no informalities in conducting a city election shall invalidate the same, if it be conducted fairly and in substantial compliance with the general laws, where applicable, and the Charter and ordinances of the city.