scantailor: Fix bug where output step would be run during config preparation
scantailor: Fix bug where output step would be run during config preparation

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