Installation Guide needs to reflect release of JBCS httpd rpm on RHEL8

Creating this sub-task to make it easier for QE to review the updates to the Apache HTTP Server installation guide to reflect the release of the JBCS httpd rpm on RHEL8.

Doc work on these updates has already been covered by the parent JBCS-1227 ticket. Coty has already given engineering approval to these updates based on JBCS-1227.

See JBCS-1277 for a summary of the issue that this fix partially addresses. This is based on an issue created by Martin Osvald at JBCS-1150.