By Alan Baldwin (Reuters) – Seven-times Formula One world champion Lewis Hamilton is confident he will win again with Mercedes this season after recent car upgrades. The 37-year-old Briton said it would be hard to win Sunday’s Austrian Grand Prix, home to rivals Red Bull and a favourite track of their championship leader Max Verstappen, but not impossible. Hamilton is the only Formula One driver to have won a race in every season he has competed, but he has now gone 11 races in a row without a victory — the longest drought of an F1 career that started with McLaren in 2007. “Earlier this year,…