title: Issue with gitlab-runner and strange x509 certificate in my installation of gitlab ee
body: <p>I'm running a server with Gitlab EE 11.7.0-ee (c02f0d4) perfectly on last months.</p>
  
  <p>Running over owned subdomain, with SSL certificate correct,</p>
  
  <p>Using the steps indicated by the Gitlab manuals try installing gitlab-runner</p>
  
  <pre><code>curl -L https://packages.gitlab.com/install/repositories/runner/gitlab-
  
  runner/script.deb.sh | sudo bash
   cat &lt;&lt;EOF | sudo tee /etc/apt/preferences.d/pin-gitlab-runner.pref
   Explanation: Prefer GitLab provided packages over the Debian native ones
   Package: gitlab-runner
   Pin: origin packages.gitlab.com
   Pin-Priority: 1001
   EOF
  sudo apt-get install gitlab-runner
  </code></pre>
  
  <p>After this I hav tried to register my first shared runner</p>
  
  <ol>
  <li>Go to admin/runners </li>
  <li>On shel run command for register</li>
  </ol>
  
  <pre><code>gitlab-runner register
  Runtime platform                                    arch=amd64 os=linux pid=8467 revision=8bb608ff version=11.7.0
  Running in system-mode.
  
  Please enter the gitlab-ci coordinator URL (e.g. https://gitlab.com/):
  https://gitlab.castris.com/
  Please enter the gitlab-ci token for this runner:
  zBTcN59V-GGGGGGGGGGG
  Please enter the gitlab-ci description for this runner:
  [gitlab]: test
  Please enter the gitlab-ci tags for this runner (comma separated):
  test
  ERROR: Registering runner... failed                 runner=zBTcN59V status=couldn't execute POST against https://gitlab.castris.com/api/v4/runners: Post https://gitlab.castris.com/api/v4/runners: x509: certificate is valid for m169-571.powervow.com, not gitlab.castris.com
  PANIC: Failed to register this runner. Perhaps you are having network problems 
  </code></pre>
  
  <pre><code>cat /etc/gitlab-runner/config.toml
  concurrent = 1
  check_interval = 0
  
  [session_server]
    session_timeout = 1800
  </code></pre>