TALLINN, Estonia — Estonia’s president, a former U.S. citizen, is likely to win re-election Monday in a country whose economy stands out as one of the most stable in the debt-ridden 17-nation eurozone. The presidential vote takes place in Parliament, where the 57-year-old incumbent, Toomas Hendrik Ilves, has the backing of Prime Minister Andrus Ansip’s Reform Party and its conservative partner IRL.