SAG-AFTRA has accused Telemundo of censorship for refusing to air a 30-second ad that accuses its parent company, NBCUniversal, of a "double standard" when it comes to paying performers on its Spanish-language network. "Hay algo que NBCUniversal no quiere que sepas sobre Telemundo," the union says. "NBCUniversal doesn't want you to know something about Telemundo." Watch the ad above. Produced in-house, the ad is part of the union's ongoing campaign to shame NBCUniversal…