JOHANNESBURG – Oprah Winfrey says she will close the school for underprivileged girls she set up in South Africa two decades ago at the end of next year. Winfrey opened the Oprah Winfrey Leadership Academy for Girls in 2007 after being inspired by conversations with former South African President Nelson Mandela about the transformative power of educating girls. He was among the guests at the school's opening ceremony. Winfrey's charitable foundation ran and funded the school, but it was always part of the agreement that the academy campus near Johannesburg be ultimately handed over to the provincial education department, the academy…