METALS-Shanghai copper slips after U.S. casts doubt on trade deal

(Adds Shanghai closing prices, updates London prices) BEIJING, May 24 (Reuters) - Shanghai copper prices snapped a five-day winning streak to end lower on Thursday, after U.S. President Donald Trump said any trade deal with China would "need a different structure" and Washington launched a probe into auto imports that could lead to new tariffs. Copper had rallied at the start of the week after U.S. Treasury Secretary Steven Mnuchin said the prospect of a U.S.-China trade war, following