The default nginx config file on centos/rocky includes a server
section listening on port 80 and [::]:80. There is no way to disable
this other than to adjust the configuration file.
This patch supplies a modified version of the centos nginx config
file which does not include a default server section.
A systemd drop in is installed to override the nginx service
ExecStart which starts the service using the modified configuration
file.
Change-Id: If7674a750e5316feb4d0fcff8cd0f4df7a67ffbb