Fixes ls: cannot access vendor/nginx: No such file or directory in debug mode
Fixes ls: cannot access vendor/nginx: No such file or directory in debug mode

Error prevented slug compilation if debug mode was turned on and threw the following error:

ls: cannot access vendor/nginx: No such file or directory
CHH/heroku-buildpack-php,jstacoder/heroku-buildpack-php-1,Scalingo/php-buildpack,ryosuzuki/php-buildpack,stof/heroku-buildpack-php,OKAMca/heroku-buildpack-php,OKAMca/heroku-buildpack-php,nsg/dokku-buildpack-picocms,Jonatasmz/php-buildpack,pierredup/packager-buildpack-php,mraymond/heroku-buildpack-php,stof/heroku-buildpack-php,Scalingo/php-buildpack,penciu/apache,AlphaStaxLLC/heroku-buildpack-php-custom,AlphaStaxLLC/heroku-buildpack-php-custom,briankilgore/heroku-buildpack-php-prod,Jonatasmz/php-buildpack,CHH/heroku-buildpack-php,penciu/apache,ryosuzuki/php-buildpack,bobmaerten/dokku-buildpack-php,CHH/heroku-buildpack-php,cachethq/cachet-buildpack,nsg/dokku-buildpack-picocms,OKAMca/heroku-buildpack-php,jstacoder/heroku-buildpack-php-1,mraymond/heroku-buildpack-php,AlphaStaxLLC/heroku-buildpack-php-custom,penciu/apache,bobmaerten/dokku-buildpack-php,pierredup/packager-buildpack-php,stof/heroku-buildpack-php,Scalingo/php-buildpack