Indignity seems to pile upon indignity for Leonardo DiCaprio these days.First, DiCaprio gets jobbed out of an Oscar nomination in “Titanic,” a film that found everything nominated but the iceberg. Now, the Disney Channel has unearthed several episodes of the ABC comedy “Growing Pains” from the 1991-92 season that featured DiCaprio in a recurring role as a homeless boy named Luke. And when is the channel airing these humble-beginnings segs? Why, starting today, during the week lead-ing up to the March 23 Academy Awards. The show runs on Disney daily at 5:30 p.m. and 6 p.m. Take that, glamour boy.