You need to either disable SELinux alltogether (in the /etc/selinux/config file change "SELINUX=enforcing" into "SELINUX=permissive" and reboot) or disable it specifically for HTTP (the semanage permissive -a httpd_t command).
/etc/selinux/config
SELINUX=enforcing
SELINUX=permissive
semanage permissive -a httpd_t