By Jibran Ahmad PESHAWAR, Pakistan (Reuters) -Gunmen killed a Christian priest and wounded another as the clerics drove home from church in Pakistan’s northwestern city of Peshawar on Sunday, police said. Two attackers on a motorcycle opened fire on the car on the city’s ring-road, killing Pastor William Siraj instantly, officers added. No one immediately claimed responsibility for the shooting in a city where scores of people died in a twin suicide bombing outside a church in 2013 – one of the deadliest attacks on Pakistan’s Christian minority. Azad Marshall, the most senior bishop in the Chu…