Patch taken from Sabberworm/PHP-CSS-Parser#115 as specified in moodle_readme.txt
This version includes a fix[1] contributed by Frédéric Massart investigating our compilation time issues, which significantly improves the speed of processing font awesome. Thanks, Fred! [1] https://github.com/sabberworm/PHP-CSS-Parser/pull/120
REMOVE ME ONCE Sabberworm/PHP-CSS-Parser#115 is merged Part of MDL-55071
Part of MDL-55071