Scrutinizer Auto-Fixes

@tomkyle requested this pull request.

This patch was automatically generated as part of the following inspection:
https://scrutinizer-ci.com/g/tomkyle/ResponsivePicture/inspections/ad25f3ff-22ad-4335-acb1-39c896cbc829

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