You are looking at the Apache Access log (so the list of requests to your site). The second request comes from ::1 which is the IPv6 address of localhost (so your server). The last parameter (Apache/2.4.6 (CentOS) PHP/5.6.33 (internal dummy connection)) isn’t an error, but the user agent of the visitor, which tells you that those requests come from Apache. (Keep in mind that 2.4.6 seems to be pretty old, so if your distribution doesn’t backport security fixes, there could be some vulnerabilities)