FRANKFURT (Reuters) - Commerzbank AG on Thursday said its 2019 profit would be lower than last year, partly due to the impact of euro zone monetary policy that has pressured margins.The German bank, which reported a 35% jump in its third-quarter net profit, had already flagged that revenue would also shrink this year against a weaker economic backdrop The state-backed bank, which is restructuring after a failed merger attempt with Deutsche Bank , also cited trade conflicts and expectations for..