KINSHASA (Reuters) – Uganda and the Democratic Republic of Congo on Wednesday extended a joint military operation launched late last year against Islamist insurgents in east Congo, the operation’s spokesperson said. Uganda sent at least 1,700 troops to its central African neighbour in December to help fight a violent rebel group known as the Allied Democratic Forces (ADF) – the largest foreign intervention in Congo in over a decade aside from a United Nations peacekeeping operation. Initially meant to last six months, Operation Shujaa was extended on Wednesday despite an earlier announcement b…