Fix EZP-21933: [SensioLabsInsight] Unused method, property, variable or parameter

See:
* https://jira.ez.no/browse/EZP-21933
* https://insight.sensiolabs.com/projects/0885c0ce-4b9f-4b89-aa9c-e8f9f7a315e0/analyses/9#rule-35-020