minor fix to MultiApplyTransforms [skip ci]
minor fix to MultiApplyTransforms [skip ci]

oesteban/fmriprep,poldracklab/fmriprep,poldracklab/fmriprep,oesteban/preprocessing-workflow,poldracklab/preprocessing-workflow,oesteban/preprocessing-workflow,oesteban/fmriprep,oesteban/fmriprep,poldracklab/fmriprep,poldracklab/preprocessing-workflow