title: Service hold-off time over, scheduling restart in Caddy service
body: <p>I have a Ubuntu 16.04 server where I have installed Caddy as HTTP server. I also have some subdomains pointing to that server. 
  I was pointing one of those subdomains to the wrong IP, and now I have:</p>
  
  <pre><code>caddy.service: Service hold-off time over, scheduling restart.
  </code></pre>
  
  <p>I tried restarting the service but I get the same result. Also modified the <code>/lib/systemd/system/caddy.service</code> file, and now the service block looks like:</p>
  
  <pre><code>[Service]
  Restart=on-failure
  StartLimitInterval=86400
  StartLimitBurst=500000
  RestartSec=3
  </code></pre>
  
  <p>I restarted the daemon, but the same result. Now I get:</p>
  
  <pre><code>Activating privacy features... 2018/04/17 23:32:24 [INFO][sub.domain.com] acme: Obtaining bundled SAN certificate
  Apr 17 23:32:24 ubuntu-apps caddy[22434]: 2018/04/17 23:32:24 [INFO][] Certificate written to disk: /etc/ssl/caddy/acme/acme-v02.api.letsencrypt.org/sites/.crt
  Apr 17 23:32:24 ubuntu-apps caddy[22434]: 2018/04/17 23:32:24 open /etc/ssl/caddy/acme/acme-v02.api.letsencrypt.org/sites/sub.domain.com/sub.domain.com.crt: no such file or directory
  Apr 17 23:32:24 ubuntu-apps systemd[1]: caddy.service: Main process exited, code=exited, status=1/FAILURE
  Apr 17 23:32:24 ubuntu-apps systemd[1]: caddy.service: Unit entered failed state.
  Apr 17 23:32:24 ubuntu-apps systemd[1]: caddy.service: Failed with result 'exit-code'.
  Apr 17 23:32:25 ubuntu-apps systemd[1]: caddy.service: Service hold-off time over, scheduling restart.
  </code></pre>
  
  <p>Probably is Let's Encrypt the one that is rejecting me? what else can I do in order to force the restarting?</p>