Correction to do_versions() in 53676

Affect on curve radius only if offset/extrude was used,
otherwise radius could have been used for other things
(like controlling hair) which will likely break
compatibility.

Reported by Tube project guys.

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@53714 954f8c5b-7b00-dc11-b283-0030488c597c