Scrutinizer Auto-Fixes

@prisis requested this pull request.

This patch was automatically generated as part of the following inspection:
https://scrutinizer-ci.com/g/prisis/Slim/inspections/50411cd5-fbc0-4ac5-82c9-06c174241ac1

Enabled analysis tools:
 - PHP Analyzer
 - PHP PDepend
 - PHP Similarity Analyzer
 - PHP Change Tracking Analyzer