Fixed problem with uncaught TypeError exception for some CollapsibleColumns plugin configurations

[wszymanski]

Context

As the title says. Just added an extra conditional.

How has this been tested?

Manual test with different configurations.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature or improvement (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Additional language file or change to the existing one (translations)

Related issue(s):

1. https://github.com/handsontable/dev-handsontable/issues/1500

Affected project(s):

• handsontable
• @handsontable/angular
• @handsontable/react
• @handsontable/vue
• @handsontable/vue3

Checklist:

• I have reviewed the guidelines about Contributing to Handsontable and I confirm that my code follows the code style of this project.
• My change requires a change to the documentation.

[github-actions]

Launch the local version of documentation by running:

npm run docs:review cce24edc479dc18907f29e9fe8e747373d2fa4e3