Follow up to #11195

I got following error (when doing gradle run from IntelliJ):

• java.lang.reflect.InaccessibleObjectException:
• Unable to make private static void org.controlsfx.control.textfield.TextFields.setupClearButtonField(javafx.scene.control.TextField,javafx.beans.property.ObjectProperty) accessible:
• module org.controlsfx.controls does not "opens org.controlsfx.control.textfield" to module org.jabref

Mandatory checks

• Change in CHANGELOG.md described in a way that is understandable for the average user (if applicable)
• Tests created for changes (if applicable)
• Manually tested changed features in running JabRef (always required)
• Screenshots added in PR description (for UI changes)
• Checked developer's documentation: Is the information available and up to date? If not, I outlined it in this pull request.
• Checked documentation: Is the information available and up to date? If not, I created an issue at https://github.com/JabRef/user-documentation/issues or, even better, I submitted a pull request to the documentation repository.