BUG: added copy of image dimension in msct_image
BUG: added copy of image dimension in msct_image

Former-commit-id: af8208bcdaaa8cc69b4d3c5e7f9c4fdfd7f8b189
Former-commit-id: 1a27b8bdce7c8a32ef80be959eac90ba59050b02
3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox