Fix rights to local_settings.d for dockerized Horizon

For some reasonf that directory doesn't have r/x rights, so when
compress is ran as root, it can access config files in it, but when
horizon is run by apache, it can't, and expects different theme files,
thus failing with OfflineGenerationError. Giving apache access to that
directory fixes the problem and makes the custom theme work.

Closes-bug: #1730911
Change-Id: I53f6db23b036bc9b5a689bbac958550f384194c6

docker/services/horizon.yaml

@@ -105,6 +105,10 @@ outputs:
             - path: /usr/share/openstack-dashboard/openstack_dashboard/local/
               owner: apache:apache
               recurse: false
+            # FIXME Our theme settings are there
+            - path: /usr/share/openstack-dashboard/openstack_dashboard/local/local_settings.d/
+              owner: apache:apache
+              recurse: false
       docker_config:
         step_2:
           horizon_fix_perms: