Country musician John Rich recently divulged a secret about the late Rush Limbaugh—a donation to St. Jude Children’s hospital. “When I was on Celebrity Apprentice, Rush Limbaugh made a donation of $100,000 dollars to St. Jude Children’s Hospital to support them, and my mission on the TV Show under the condition that he remained anonymous,” wrote the country star on Twitter. “I never said a word until now. He will be missed #RIPRushLimbaugh,” he added. The iconic conservative radio host passed away on Wednesday at age 70. He was diagnosed with cancer last year. “This day has been one of the most difficult days in recent memory, for me, because I’ve known this moment was coming,” Limbaugh said on the air last year. “I can’t help but feel that I’m letting everybody down with this. But the upshot is that I have been diagnosed with advanced lung cancer.” President Donald …