关闭 gitlab中的 letsencrypt

执行gitlab-ctl reconfigure，一直报letsencrypt相关的错误

Recipe: letsencrypt::enable
  * ruby_block[http external-url] action run (skipped due to only_if)
  * directory[/srv/gitlab_ssl] action create (up to date)
  * acme_selfsigned[support.rt-thread.com] action create
    * file[support.rt-thread.com SSL selfsigned key] action create_if_missing (up to date)
    * file[support.rt-thread.com SSL selfsigned crt] action create_if_missing (up to date)
    * file[support.rt-thread.com SSL selfsigned chain] action create_if_missing (skipped due to not_if)
     (up to date)
Recipe: letsencrypt::http_authorization
  * letsencrypt_certificate[support.rt-thread.com] action create
    * acme_certificate[staging] action create
      * file[support.rt-thread.com SSL key] action create_if_missing (up to date)

但我没开letsencrypt功能啊，搜了一下发现默认是打开的，手动关闭就行了。

letsencrypt['enable'] = false

因为我用外部证书，如果需要使用letsencrypt自动申请证书，则需要配置好nginx的目录，让letsencrypt完成验证。

参考链接：
https://stackoverflow.com/questions/59069753/turn-off-lets-encrypt
https://www.manongdao.com/article-1708173.html