The optimism on display just two months ago when Singapore Transport Minister Ong Ye Kung pledged to reopen the city state and its tourism-reliant economy has taken a beating after a possible local coronavirus case was found aboard one of Royal Caribbean ships.In the early hours of Wednesday morning, the 1,680 passengers and 1,148 crew on Quantum of the Seas – enjoying day three of a four-day “cruise to nowhere” – were alerted to an announcement that a suspected case of Covid-19 had been…