By John Revill and Mimosa Spencer ZURICH (Reuters) -Cartier jewellery owner Richemont (SIX:) reported a dip in quarterly sales on Friday, as the luxury goods group largely offset tougher conditions in China with growth elsewhere. The owner of Swiss watchmakers including IWC, Jaeger-LeCoultre and Piaget said sales fell by 1% at constant exchange rates to 4.81 billion euros ($5.19 billion), slightly above analyst consensus forecasts of 4.78 billion euros cited