MOSCOW, June 8 (Reuters) - For more than 15 months Russia has been fighting a war in Ukraine that the Kremlin refused to call a war - but that is changing: President Vladimir Putin is using the word "war" more often. When Putin sent troops into Ukraine on Feb. 24 last year, he called it "a special military operation" - a euphemism the Kremlin, Russian ministers and state media mostly stuck to, even coining a new Russian acronym, the "SVO". Calling the conflict a war was effectively outlawed for the Russian media by a series of very broad laws soon...