(This Aug 7 story corrects to fix reporting credits, no change to text) BORGO VIRGILIO, Italy (Reuters) – Heatwaves sweeping Europe this summer have brought not just record high temperatures and scorched fields: the drought-stricken waters of Italy’s River Po are running so low they revealed a previously submerged World War Two bomb. Military experts defused and carried out a controlled explosion on Sunday of the 450-kg (1,000-pound) bomb, which was discovered on July 25 near the northern village of Borgo Virgilio, close to the city of Mantua. “The bomb was found by fishermen on the bank of th…