You just need to uncomment this lines
listen.owner = www-datalisten.group = www-datalisten.mode = 0666
In this case you don't need use manipulation with chmod or chown.
I believe you could do:
sudo chown www-data.www-data /var/run/php5-fpm.sock
*Substitute www-data.www-data with whatever user Apache / PHP-FPM run under.
i dont know how to fix that but problem is related to permissions of /var/run/php5-fpm.sock
you have to chmod 666 /var/run/php5-fpm.sock