gitlab-ctl reconfigure error letsencrypt_certificate even when letsencrypt['enable'] = false

my gitlab.rb

external_url "https://myDomain:myPort"
letsencrypt['enable'] = false
nginx['redirect_http_to_https'] = true
nginx['ssl_certificate'] = "/etc/gitlab/ssl/gitlab.crt"
nginx['ssl_certificate_key'] = "/etc/gitlab/ssl/gitlab.key"

i generate my own certificates because port 80 and 443 are already used.

but when iam run Recipe: letsencrypt::enable

its says

` Recipe: letsencrypt::enable ...

  Error executing action `create` on resource 'acme_certificate[staging]'
  ================================================================================
  
  RuntimeError
  ------------
  [myDomain] Validation failed for domain myDomain
  
  Cookbook Trace:
  ---------------
  /opt/gitlab/embedded/cookbooks/cache/cookbooks/acme/providers/certificate.rb:93:in `block (2 levels) in class_from_file'
  /opt/gitlab/embedded/cookbooks/cache/cookbooks/acme/providers/certificate.rb:68:in `map'
  /opt/gitlab/embedded/cookbooks/cache/cookbooks/acme/providers/certificate.rb:68:in `block in class_from_file'
  
  Resource Declaration:
  ---------------------
  suppressed sensitive resource output
  
  Compiled Resource:
  ------------------
  suppressed sensitive resource output
  
  System Info:
  ------------
  chef_version=13.6.4
  platform=ubuntu
  platform_version=16.04
  ruby=ruby 2.4.4p296 (2018-03-28 revision 63013) [x86_64-linux]
  program_name=/opt/gitlab/embedded/bin/chef-client
  executable=/opt/gitlab/embedded/bin/chef-client
  

================================================================================
Error executing action `create` on resource 'letsencrypt_certificate[myDomain]'
================================================================================

` Why gitlab runs letsencrypt? Iam using the Docker image.