Fix [#37393] Input dimensions are case sensitive in the property panel, uppercase input is misinterpreted

Typo in lowercasing code!

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk@61225 954f8c5b-7b00-dc11-b283-0030488c597c
Followup to previous r61225, the other part of the condition was also reverted! Thanks to Sergey for noting this. :)

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk@61226 954f8c5b-7b00-dc11-b283-0030488c597c