FOREX-Sterling weakens as investors fret over Carney's message, yen firm

* Dollar drifts lower vs yen, awaits US GDP revision * Geopolitical concerns underpin the yen (Recasts, adds details) LONDON, June 25 (Reuters) - Sterling stayed under pressure for a second day on Wednesday, as investors cut favourable bets on the currency after Bank of England governor cooled expectations of an interest rate hike later this year. The situation in Iraq was also supporting the ...