All city officers elected by the people shall possess the qualifications set out in Article VI of the Constitution. In addition, when the city is divided into electoral districts for the purpose of electing members of the council, council members shall reside in the district they represent. When any elected city officer ceases to meet all of the qualifications for holding office pursuant to the Constitution, or when a council member ceases to reside in an electoral district that he was elected to represent, the office is ipso facto vacant. (1973, c. 609.)