live.step load with dictionary fold_pitch bug

I think there's a bug with live.step being loaded by a dictionary and including a "fold_pitch" key.

If I include the fold_pitch key in the dict, it's values get set to extra2's values.

so if extra2 = [127, 127, 127, 127,]
and fold_pitch = [60, 64]

after you load the dictionary extra2 becomes:
extra2 = [60, 64, 127. 127, 127]

you can see in the patch