PHILADELPHIA — A federal jury acquitted Philadelphia City Councilmember Kenyatta Johnson on federal bribery charges Wednesday, rejecting what his lawyers described as an overreaching prosecution that threatened to end his political career. The panel of seven women and five men took less than four hours Wednesday to rebuff the government’s accusations that Johnson had sold the powers of his office to two nonprofit executives who funneled their payoffs through a sham $67,000 consulting contract with the Council member’s wife, Dawn Chavous. Instead, the jury’s decision appeared to affirm defense …