When Canadian country duo the Reklaws appeared on an episode of "America's Got Talent" last month, some fans were confused. Among the chatter on social media: Why would an established, award-winning band seek the approval of Simon Cowell and other show judges? Siblings Jenna and Stuart Walker said they simply couldn't turn down an opportunity to expand their musical career outside Canada. “We could grind away in Nashville for the next 10 years or we could say yes to this competition and see if we can open that door a lot quicker,” Jenna Walker said in a recent video call…