Lift. Don't lift maximally (1-3 rep range). At your age, I wouldn't go any lower than 8 reps and prob use the 8-12 rep range. It's not so much the stunted growth that's a concern but your body is producing a hormone called Relaxin (seriously) and you're not as structurally sound (pregnant women secrete the same hormone).
But finding another activity besides lifting wouldn't be a bad idea...go play man. Doesn't matter what it is-gymnastics, swimming, soccer...just get out and be active.
