KHARTOUM (Reuters) – The deputy head of Sudan’s military-led Sovereign Council said on Saturday a U.N. envoy should be working as a “facilitator and not a mediator”, signalling an apparent tougher line towards international efforts to resolve a political crisis. A United Nations mission led by special envoy Volker Perthes began talks this month to help resolve the standoff which followed a coup last year. Previously, the Sovereign Council has welcomed the U.N. initiative, and Perthes has said the army had no objections to his presence. “The head of the United Nations’ Integrated Transition Mis…