INST: installation is now possible without being admin
INST: installation is now possible without being admin

Former-commit-id: ca4a765072ab40c9702c0923f91668c2c4ed988c
Former-commit-id: e806aea7789c125ed2bf551a61a64da6fbf1f6c8
3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox