B’klyn model says back-breaking part in ‘MIB 3’ ruined her career

She broke her back for “Men in Black.” Brooklyn model Danika Gerner, 23, donned a 30-pound sheet-metal dress and 6-inch heels to play an alien from the planet Glamoura during filming of “MIB 3” in Manhattan last year. Gerner claims the intergalactic get-up caused her to suffer a herniated disc…