The singer R. Kelly was correctly sentenced to 20 years in prison on child sex convictions in Chicago, a federal appeals court ruled Friday.Jurors in 2022 convicted the Grammy Award-winning R&B singer, born Robert Sylvester Kelly, on three charges of producing child porn and three charges of enticement of minors for sex.In his appeal, Kelly argued that Illinois’ former and shorter statute of limitations on child sex prosecutions should have applied to his Chicago case rather than current law permitting charges while an …