LONDON (Reuters) – Prince William and his wife Kate took over the airwaves of every radio station in the United Kingdom on Friday to deliver a message encouraging the British public to look out for anyone who might be feeling lonely. The “Mental Health Minute”, featuring the two royals, was played out on more than 500 stations just before 11 a.m. (1000 GMT), with the organisers saying an estimated 20 million people would hear the broadcast. “Hello, I’m Catherine, and I’m William. And we’d like to talk for just one minute about loneliness,” they said. Addressing mental health issues is a key ca…