“The Book of Mormon” creators Trey Parker, Matt Stone and Robert Lopez stopped by “The Late Show with Stephen Colbert” to celebrate the hit musical’s 15th anniversary and reflect on the Mormon Church’s “super nice” reaction to it. Colbert asked the trio if any of them felt any trepidation about the musical’s most satirical, boundary-pushing moments, to which Stone, who co-created “South Park” with Parker, said, “It’s just what we do.” The “Late…