Correct typo in versions
Correct typo in versions

There are several references to version 2.3.19 as latest of 2.x releases.
While there is a 2.3.19 tag, it hasn't been build and released to the stable channel.

https://downloads.chef.io has 2.3.16 as latest

Our YUM repo has the following versions:-

```
[root@chef ~]# yum search chef-backend --showduplicates
Last metadata expiration check: 3:29:02 ago on Tue 01 Mar 2022 18:47:46 GMT.
======================================================== Name & Summary Matched: chef-backend ========================================================
chef-backend-3.0.0-1.el8.x86_64 : The full stack of chef-backend
chef-backend-2.3.16-1.el8.x86_64 : The full stack of chef-backend
chef-backend-2.1.0-1.el7.x86_64 : The full stack of chef-backend
chef-backend-2.2.0-1.el7.x86_64 : The full stack of chef-backend
[root@chef ~]#
```
chef/chef-server,chef/chef-server,chef/chef-server,chef/chef-server,chef/chef-server,chef/chef-server