Jury selection got underway Monday at R. Kelly’s federal trial in his hometown of Chicago, where the R&B singer faces charges that he rigged his 2008 state child pornography trial. He is accused of threatening and paying off a girl he allegedly filmed himself having sex with when he was around 30 and she was no older than 14.Jurors acquitted Kelly on all charges in that 2008 trial, some explaining later that they felt they had no choice because the girl did not testify. The woman, now in her 30s and referred to in …