SPRINGFIELD — A longtime aide to House Speaker Michael J. Madigan has been fired for making unwanted advances toward a woman and “inappropriate conduct,” the speaker announced today.Madigan said in a statement this morning that Kevin Quinn, who worked for the top Democrat’s political organization for about 20 years, is no longer an employee for his political committees and won’t work in his government office in the future, either.Quinn is the brother of 13th Ward Ald. Marty Quinn — with …