Create your own Git server

I have a centOS 7 server, in which I have installed gitlab, to which I need to change port 80 to 8080. To be able to have apache running on port 80.

I enter the gitlab gitlab.rb configuration file adding the following:

external_url "http://xxx.xxx.xxx.xxx:8080"

nginx['proxy_set_headers'] = { "X-Forward-Port" => "8080", "http://xxx.xxx.xxx.xxx" => "<xxx.xxx.xxx.xxx>:8080" }

gitlab-ctl reconfigure

gitlab-ctl restart

When I try to enter Gitlab with the address link a blank page with the gitlab logo and text is displayed

Any idea that I may be overlooked ?, I have to change the port somewhere else for Gitlab to load correctly.