LONDON (Reuters) -Britain said on Monday it welcomed Afghanistan’s decision to release five British nationals who had travelled there against official advice. “These British nationals had no role in the UK government’s work in Afghanistan and travelled to Afghanistan against the UK government’s travel advice. This was a mistake,” Britain’s Foreign, Commonwealth and Development Office said in a statement. “The UK government regrets this episode.” A former BBC cameraman, Peter Jouvenal, was among the detainees released, BBC News reported. “We are grateful to the thousands of people who have supp…