HARARE, Nov 20 (Reuters) - Southern Africa's regional bloc on Wednesday extended by a year its troop deployment in Democratic Republic of Congo, where it is helping the government fight rebel groups. The Southern African Development Community (SADC) deployed the mission in Congo, a major producer of metals like cobalt and copper, in December 2023 with a one-year mandate. A communique issued after regional leaders met in Zimbabwe's capital Harare expressed concern at the security and...