Redirect Geo git push operations to primary external URL

Instead of redirecting to the primary Geo internal URL in a git push
operation, this now always redirects to the external URL.

This didn't work previously with internal URLs that were not public,
or inaccessible to the regular users who may be pushing through
a Geo secondary site.

Changelog: fixed
EE: true

ee/app/controllers/ee/repositories/git_http_client_controller.rb

@@ -220,7 +220,7 @@ module EE
                  File.join(geo_secondary_referrer_path_prefix, geo_request_fullpath_for_primary)
                end
 
-        ::Gitlab::Utils.append_path(::Gitlab::Geo.primary_node.internal_url, path)
+        ::Gitlab::Utils.append_path(::Gitlab::Geo.primary_node.url, path)
       end
 
       def geo_secondary_referrer_path_prefix

ee/spec/requests/git_http_geo_spec.rb

@@ -13,8 +13,9 @@ RSpec.describe "Git HTTP requests (Geo)", :geo do
   let_it_be(:project_no_repo) { create(:project, :private) }
 
   let_it_be(:primary_url) { 'http://primary.example.com' }
+  let_it_be(:primary_internal_url) { 'http://primary-internal.example.com' }
   let_it_be(:secondary_url) { 'http://secondary.example.com' }
-  let_it_be(:primary) { create(:geo_node, :primary, url: primary_url) }
+  let_it_be(:primary) { create(:geo_node, :primary, url: primary_url, internal_url: primary_internal_url) }
   let_it_be(:secondary) { create(:geo_node, url: secondary_url) }
 
   let!(:user) { create(:user) }