By Tom Sims and Alexander Hübner FRANKFURT (Reuters) -Allianz spent around 140 million euros ($143.11 million) on restructuring to wind down a U.S. funds unit at the centre of a multi-billion fraud, the German insurer disclosed on Friday, an expense that added to a worse-than-expected 23% fall in quarterly profit. Allianz in May agreed to shut down the unit, Allianz Global Investors in the United States, as part of a guilty plea for securities fraud and a $6 billion settlement with U.S. law enforcement and regulators. The charge, unveiled in its second-quarter earnings report, is a remnant of …