fix code highlighting not working in print-pdf output
fix code highlighting not working in print-pdf output

bibryam/optaplanner-website,oskopek/optaplanner-website,bibryam/optaplanner-website,oskopek/optaplanner-website,psiroky/optaplanner-website,droolsjbpm/optaplanner-website,bibryam/optaplanner-website,droolsjbpm/optaplanner-website,psiroky/optaplanner-website,psiroky/optaplanner-website,oskopek/optaplanner-website,droolsjbpm/optaplanner-website