LONDON (Reuters) – Britain warned its citizens not to undertake any ‘risky activity’ on Wednesday when ambulance drivers and call handlers are due to strike over pay, leaving those with all but the most life-threatening conditions to make their own way to hospital. Speaking as tens of thousands of striking nurses formed picket lines outside hospitals, and a day before ambulance workers walk out, junior health minister Will Quince warned there would be disruption for patients. “Where people are planning any risky activity, I would strongly encourage them not to do so,” he told the BBC. Ambulanc…