By KEVIN McGILL NEW ORLEANS — Lawyers for retired NFL quarterback Brett Favre asked a federal appeals court Tuesday to revive a defamation lawsuit Favre filed against a fellow Pro Football Hall of Fame member, former tight end Shannon Sharpe, amid the backdrop of a Mississippi welfare scandal that is one of the state’s largest public corruption cases. A federal judge in Mississippi threw out the lawsuit in October, saying Sharpe used constitutionally protected speech on a sports broadcast when he criticized Favre’s connection to the welfare misspending case. Favre’s lawyer, Amit Vora, told three 5th U.S.