No surprise
Fragment of a discussion from Comments:Iranian news agency reproduces The Onion article
Certainly wouldn't put it past the Onion, but I'm inclined to think the Iranians just screwed up. They may be so acclimated to printing their own propaganda, they believe it; and with the language barrier, they could easily have just stumbled on the thing, not realized it was humor, and run with it. Not that I'm ruling anything out, but that's my inclination.