The escalating US-China trade war triggered the Hong Kong government’s trade-promotion body to downgrade on Monday its forecast for the city’s export growth.The Trade Development Council said it expected 2 per cent growth this year, down from an earlier forecast of 5 per cent.United States President Donald Trump said last week he would decide in early July whether to impose 25 per cent tariffs on US$300 billion untaxed Chinese imports after his expected meeting with President Xi Jinping at the…