archwiki: update the repository URL

Related to archlinux/infrastructure#557

roles/archwiki/defaults/main.yml

@@ -2,7 +2,7 @@ archwiki_dir: '/srv/http/archwiki'
 archwiki_domain: 'wiki.archlinux.org'
 archwiki_nginx_conf: '/etc/nginx/nginx.d/archwiki.conf'
 archwiki_user: 'archwiki'
-archwiki_repository: 'https://github.com/archlinux/archwiki.git'
+archwiki_repository: 'https://gitlab.archlinux.org/archlinux/archwiki.git'
 archwiki_version: '1.41.0-2'
 archwiki_question_answer_file: '/srv/http/archwiki/registration-question-answer.txt'