LONDON (Reuters) – Switzerland imported gold from Russia in May for the first time since the Kremlin sent troops into Ukraine in February, Swiss customs data showed on Tuesday. Switzerland is the world’s biggest refining and transit centre for gold and Russia is one of the biggest bullion producers. Western sanctions on Russia have not directly targeted commercial gold shipments but many banks, shippers and refiners stopped dealing with Russian metal after the conflict in Ukraine began. Switzerland received 3.1 tonnes of gold worth around $200 million from Russia in May, accounting for around …