INST: install_sct: minor modifs
INST: install_sct: minor modifs

Former-commit-id: 410d5e358548300b674e1ff9b3e8f0a437865ded [formerly e7503fceb58baa7ae5f7468fc59233a6bdf4771c]
Former-commit-id: 695c6dbb14d4f6e7da25ad7a8f9358d9e2436a59
Former-commit-id: 94c5f36b3783fda7865ccbcdb4cf39cc7dd64d89
neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox