DUBLIN (Reuters) - Irish consumer sentiment improved in December to post the first back-to-back monthly gain in four years as the risk of a damaging 'no-deal' Brexit receded, according to a survey published on Friday.Ireland has remained the European Union's fastest growing economy during three years of Brexit talks, but consumer confidence faltered when it seemed that its nearest neighbour could leave the bloc without agreeing to a withdrawal deal.The KBC Bank consumer sentiment index rose to..