By David Morgan WASHINGTON (Reuters) -Republican U.S. Senate candidate Herschel Walker, who has said he opposes abortion with no exceptions, faced fresh allegations on Wednesday from a second woman who said he pressured her to have an abortion and paid for the procedure after a six-year relationship with him. Walker, who hopes to unseat Democratic incumbent Senator Raphael Warnock of Georgia in a Nov. 8 election that could determine which party controls the Senate, has already denied allegations from another woman who claims he paid for her to have an abortion in 2009 and that she later gave b…