autorotate: Fix multiprocessing code
autorotate: Fix multiprocessing code

jbaiter/spreads,nafraf/spreads,nafraf/spreads,jbaiter/spreads,adongy/spreads,gareth8118/spreads,gareth8118/spreads,miloh/spreads,gareth8118/spreads,nafraf/spreads,DIYBookScanner/spreads,adongy/spreads,jbaiter/spreads,DIYBookScanner/spreads,adongy/spreads,miloh/spreads,miloh/spreads,DIYBookScanner/spreads