Document URL: 

https://access.redhat.com/documentation/en-us/red_hat_cloudforms/4.5/html/general_configuration/configuration#configuring_database_replication

Section Number and Name: 
4.4.3. Configuring Database Replication and Centralized Administration

Describe the issue: 

Central admin mechanism was removed in PR#13966[1] & UI changes were made in PR#421[2] but the section still exists and should be removed. There's an upstream discussion regarding documentation update[3].

Snapshots is following sections also need to be updated:
- 4.4.3.2. Configuring the Global Copy
- 4.4.3.3. Enabling / Disabling Centralized Administration

[1] https://github.com/ManageIQ/manageiq/pull/13966
[2] https://github.com/ManageIQ/manageiq-ui-classic/pull/421
[3] http://talk.manageiq.org/t/how-do-i-set-up-database-replication/2001/3


Suggestions for improvement: 


Additional information: 

If required, I can send a Merge request