SOCHI, Russia, Feb 10 (Reuters) - Irina Rodnina, the figure skater who lit the Olympic flame at the Sochi Games, blamed hackers on Monday for a tweet about U.S. President Barack Obama that caused a racism row. Some Western media questioned the choice of Russia's triple Olympic champion Rodnina featuring in the climax of the Games opening ceremony on Friday. A tweet on her timeline last year showed a picture of Obama which was photoshopped to add a banana in the foreground. The image angered many including the outgoing U.S. ambassador to Russia, Michael McFaul, who called it "outrageous behaviour"....