fix shearTweak (was typo setting scaleTweak instead)

[pmolodo]

Description (this won't be part of the changelog)

Title basically says it all - instead of setting shearTweak, scaleTweak was getting set (copy/paste type, I'm assuming).

Changelog

Fixed

• Fixed setting of shearTweak

Checklist (Please do not remove this line)

• [X] Make sure the Title and Description of the PR make sense and provide sufficient context for your work
• [X] Do any added files have the correct AL Apache Licence Header?
• [X] Are there Doxygen comments in the headers?
• [X] Are any new features, behaviour changes documented in the .md format documentation?
• [ ] Have you added, updated tests to cover new features and behaviour changes?
• [X] Have you filled out at least one changelog entry?