change param of 3D kernel size for T2 contrast
change param of 3D kernel size for T2 contrast


Former-commit-id: da1e9cd1976c7f9ad94e08a67f517506053b4689
neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox