A vacancy in the City Council, except the office of Mayor, shall be filled by calling a special election to be held in accordance with the applicable laws of the State of Texas; provided, however, if such vacancy occurs within ninety days of a general election, then no special election shall be called. If the Mayor Pro-Tem succeeds to the office of Mayor under the provisions of Section 3.05 of this Article III, then his/her office of councilmember shall be considered vacant within the meaning of this Section.