Connecticut is reaping an unexpected windfall from hedge funds and residents rushing to prepay next year’s taxes before the federal cap on state and local deductions kicks in. The state’s estimated personal income taxes in December and January will exceed projections by more than $900 million, Governor Dannel Malloy said in a statement Monday. A large amount of the extra revenue resulted from a federal law enacted in 2008 that required hedge fund managers who earned fees offshore to bring the profits back to the U.S. by the end of 2017.