sct_check_dependencies: remove dead code
sct_check_dependencies: remove dead code

It also happens to fail under py3k


Former-commit-id: e9c8d252bcef774bd3f06c165b9469b7c7c6b461
neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox