Carrie Underwood has vowed to be “kind” on ‘American Idol’. The ‘Before He Cheats’ hitmaker has replaced Katy Perry as a judge on the talent show and though the 41-year-old star – who shot to fame when she won the fourth series of the programme in 2005 – has pledged to be “honest” with her feedback to the contestants, she doesn’t want to crush their dreams. Speaking during a surprise appearance at SiriusXM’s ‘Music Row Happy Hour in Las Vegas’, she said: “I think I can be honest and constructive, but still kind. And I think that’s the whole point, because people are coming in and it’s dreams. …