BUG: added check on get_dimension in sct_utils
BUG: added check on get_dimension in sct_utils

Former-commit-id: d7ade8b4d9e7eab47df975981402a94b8a1fc9fd [formerly 879cda9efa327c6a6544a0e3a6d7bbea7d6da6f6]
Former-commit-id: ab1b8d45ee549268fd6e4d9ad949bf7c98859a12
Former-commit-id: d974780f9d4fdcdce2bb079697cdf3866673bf18
neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox