LONDON (Reuters) – Britain’s foreign office on Friday summoned Russian Ambassador Andrei Kelin to express “deep concern” over reports of the death of a British aid worker. “I am shocked to hear reports of the death of British aid worker Paul Urey while in the custody of a Russian proxy in Ukraine. Russia must bear the full responsibility for this,” Foreign Secretary Liz Truss said. “Those responsible will be held to account.” An official in the self-proclaimed Donetsk People’s Republic (DPR) announced Paul Urey’s death earlier in the day. His death was also confirmed by British charity Presidi…