Fix slices per frame for multiband imaging
Fix slices per frame for multiband imaging

The ImagesInAcquisition tag means "slices per volume" in previous fMRI
series; in multiband imaging, it means "slices per scan."

To fix this, count slices per volume differently for the two scan types
njvack/ge-mri-rtafni,njvack/ge-mri-rtafni