Movie review Let me just be clear up front here: Certain scenes from the original “The Devil Wears Prada” movie, from 20 years ago, are so ingrained in my brain that I frequently hear Meryl Streep’s Miranda Priestly weighing in on things in my head — and maybe you do, too. (“ Why is no one read-dy ?,” in her chilly singsong from the first movie, plays often. I mean, really, why is no one ready?) Unfortunately, she had a few things to say to me about “The Devil Wears Prada 2,” most notably, “Why is this movie so fla-at?” Sorry, Miranda; I wish I knew. RECENT MOVIE REVIEWS “The Devil Wears Prada 2,” despite reuniting the entire top-line team from the original (director David Frankel; screenwriter Aline Brosh McKenna; stars Streep, Anne Hathaway, Emily Blunt and Stanley Tucci), lacks the first movie’s playful spark; it feels like fan fiction, with everyone gamely going through the motions without finding anything fresh.…