CP-9229: Use new path for convert-legacy-stream

The previous path (.../legacy.py) was a symlink for backwards compatibility
with development and we would like to remove it before release.

Signed-off-by: Si Beaumont <simon.beaumont@citrix.com>
Merge pull request #105 from simonjbeaumont/cp-9229

CP-9229: Use new path for convert-legacy-stream