The Islamic State group on Sunday vowed “revenge” over the killing of its former leader, calling on supporters to take advantage of war in Ukraine to stage attacks in Europe. “We announce, relying on God, a blessed campaign to take revenge” over the death of Abu Ibrahim al-Qurashi and the group’s former spokesman, an audio message attributed to the group and circulated on the Telegram messaging app said. The group’s new spokesman, Abu-Omar al-Muhajjir, also called on supporters to resume attacks in Europe, taking advantage of the “available opportunity” of “the crusaders fighting each other” -…