Jay Leno has taken such a beating over his recent treatment of Conan O’Brien that the lantern-jawed comic plans to go on “The Oprah Winfrey Show” next week to try to restore his nice-guy reputation. While everyone from David Letterman to Jimmy Kimmel has blasted Leno for maneuvering O’Brien off the air, Oprah will treat him with kid gloves. “Oprah and Jay love each other,” said a source. “They talk constantly.” An NBC rep said, of Leno’s “Oprah” appearance, “We’re still discussing it.”