BUG: fix bug occurring when data are not in RPI orientation, set_orientation does not overwrite the labels as the label index increases in the "for" loop
BUG: fix bug occurring when data are not in RPI orientation, set_orientation does not overwrite the labels as the label index increases in the "for" loop

Former-commit-id: 52f5f47c4c1ff68d0a5f7c80d782a00530072df1 [formerly 4c10bdb4aa4c2d179246041b7b348f582a268094]
Former-commit-id: 761e1ba5598632b144fa93080f9aeb7578f308a6
Former-commit-id: baeab646372252a43bcf16e9a96c0f5dbdd42fe2
neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox