It does have that one song, I’ll give it that. But beyond that, this is a truly dreadful and cheap-feeling follow-up to "Saturday Night Fever," and it took six years to even get made. It's hard to understand who believed this was worthwhile—aside from whoever stood to profit—but John Travolta returns as “Tony,” now attempting to make it on the Broadway stage. He’s different now; he resists drinking, talks with a refi…