MOSCOW, Sept 26 (Reuters) - Viktor Sokolov, the commander of Russia's Black Sea Fleet and one of Russia's most senior navy officers, was shown on Tuesday attending a video conference, a day after Ukrainian special forces said they had killed him. In video and photographs released by the Russian defence ministry, Sokolov was shown apparently taking part in a video conference with Defence Minister Sergei Shoigu and other top admirals and army chiefs. Ukraine's special forces said on Monday they had killed Sokolov, Moscow's top admiral in Crimea, along with 33 other officers in a missile attack last week on...