fix optional multifeilds
fix optional multifeilds

ethantang95/DIGITS-GAN,ethantang95/DIGITS,bygreencn/DIGITS,jmancewicz/DIGITS,Deepomatic/DIGITS,ethantang95/DIGITS,TimZaman/DIGITS,dongjoon-hyun/DIGITS,Deepomatic/DIGITS,jmancewicz/DIGITS,gheinrich/DIGITS-GAN,ethantang95/DIGITS,TimZaman/DIGITS,jmancewicz/DIGITS,TimZaman/DIGITS,bygreencn/DIGITS,dongjoon-hyun/DIGITS,TimZaman/DIGITS,Deepomatic/DIGITS,dongjoon-hyun/DIGITS,Lucaszw/DIGITS,Lucaszw/DIGITS,gheinrich/DIGITS-GAN,gheinrich/DIGITS-GAN,ethantang95/DIGITS-GAN,Lucaszw/DIGITS,gheinrich/DIGITS-GAN,ethantang95/DIGITS-GAN,ethantang95/DIGITS,bygreencn/DIGITS,bygreencn/DIGITS,dongjoon-hyun/DIGITS,Deepomatic/DIGITS,ethantang95/DIGITS-GAN,jmancewicz/DIGITS,Lucaszw/DIGITS