LONDON (Reuters) – Russia’s ambassador in London said on Tuesday that Britain had asked for Moscow’s help in connection with two British citizens sentenced to death in a Russian-backed separatist region for fighting for Ukraine. A court in the breakaway Donetsk People’s Republic (DPR) in eastern Ukraine this month sentenced Britons Aiden Aslin and Shaun Pinner and Moroccan Brahim Saadoun to death for “mercenary activities”. Their families deny that the trio, who were contracted by the Ukrainian armed forces, are mercenaries. Britain says its citizens were regular soldiers and should be exempt …