REF: msct_image>loadFromPath: removed check if file exist
REF: msct_image>loadFromPath: removed check if file exist

Former-commit-id: 77c98134efa533adbd127ae0ff862de83ca8443b
Former-commit-id: 59b994a1ca30393a23b726cab90d1630757cc651
3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox