Fix conference_dir permissions

Allow the http user to access the conference home directory.

roles/conf_archlinux/tasks/main.yml

@@ -14,7 +14,7 @@
   register: release
 
 - name: fix home permissions
-  file: state=directory owner={{ conference_user }} group={{ conference_user }} mode=0750 path="{{ conference_dir }}"
+  file: state=directory owner={{ conference_user }} group=http mode=0750 path="{{ conference_dir }}"
 
 - name: create static conf.archlinux.org dir
   file: state=directory owner={{ conference_user }} group={{ conference_user }} mode=0755 path="{{ static_conference_dir }}"