OPT: Correct header after padding using qform instead of sform. (fix #518)
OPT: Correct header after padding using qform instead of sform. (fix #518)

3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox