A UK immigrant and career criminal charged with a bloody killing spree in Georgia that claimed the life of a Department of Homeland Security employee and two others died in jail on Tuesday night, according to authorities.  Olaolukitan Adon-Abel, 26, was discovered dead in his jail cell. Authorities performed life-saving measures on the convicted felon, but he was ultimately pronounced dead, according to the DeKalb County Sheriff’s Office.  His cause of death is not yet known, but officials do not suspect foul play and will conduct an internal review, cops said.  Adon-Abel, a convicted felon immigrant who was naturalized under…