An official gauge of China’s factory activity expanded at a faster pace in July, as improving demand inside and outside the country kept the recovery of the world’s second-largest economy on track. China’s official manufacturing purchasing managers index rose to 51.1 in July from 50.9 in June, the National Bureau of Statistics said Friday, beating economists’ expectations and marking the fifth consecutive month that the closely watched measure of China’s factory activity topped the 50 mark that separates expansion…