By Gertrude Chavez-Dreyfuss NEW YORK (Reuters) -The dollar fell for a second straight session on Tuesday, after hitting a 19-month peak at the end of last week, on weaker-than-expected U.S. economic data and after Federal Reserve officials pushed back against aggressive rate hikes this year, lifting risk appetite. As the dollar eased, risk-sensitive currencies such as the Australian dollar, euro, and British pound gained. After falling nearly 5% in January, world equities started February slightly firmer and currency markets have also changed course. A chorus of Fed officials said on Monday th…