fix type for margin argument in CropForegroundd (#2234)
fix type for margin argument in CropForegroundd (#2234)

Signed-off-by: ambroslins <6280e0173f955326579654fc5d997d587fb93bd3@gmail.com>
Project-MONAI/MONAI,Project-MONAI/MONAI,Project-MONAI/MONAI,Project-MONAI/MONAI