INST: install_sct: minor changes
INST: install_sct: minor changes

Former-commit-id: c107b363cf3b14d9928f6f7fc7c33e80c3503883
Former-commit-id: b32393101b766aa098bdcb8ec0c88c0157830ee6
3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox