Centos 7 Squid vs Squid 3

After installing Ajenti, I still have the option to install Squid even though squid is already installed.  It is telling me to install Squid 3 and I am unable to find any difference between the version of Squid I have installed and Squid 3.

In the squid plug-ins panel it shows: 

'Application binary Squid 3' with an icon for me to install Squid.   When I try to install, I get a message saying it is already installed.

Installed Packages
Name        : squid
Arch        : x86_64
Epoch       : 7
Version     : 3.5.20
Release     : 2.el7_3.3
Size        : 10 M
Repo        : installed
From repo   : updates
Summary     : The Squid proxy caching server
URL         : http://www.squid-cache.org
License     : GPLv2+ and (LGPLv2+ and MIT and BSD and Public Domain)
Description : Squid is a high-performance proxy caching server for Web clients,
            : supporting FTP, gopher, and HTTP data objects. Unlike traditional
            : caching software, Squid handles all requests in a single,
            : non-blocking, I/O-driven process. Squid keeps meta data and
            : especially hot objects cached in RAM, caches DNS lookups, supports
            : non-blocking DNS lookups, and implements negative caching of failed
            : requests.
            :
            : Squid consists of a main server program squid, a Domain Name System
            : lookup program (dnsserver), a program for retrieving FTP data
            : (ftpget), and some management and client tools.

Temporary Fix

I am able to use the plug-in by creating a symbolic link between my squid file /usr/sbin/squid and /usr/sbin/squid3.  To use the configurations I created a symbolic link between /etc/squid and  /etc/squid3.