Update conditional for gitlab_letsencrypt_enable using new variable name

Author: williampiv

templates/gitlab.rb.j2

@@ -20,7 +20,7 @@ nginx['ssl_certificate'] = "{{ gitlab_ssl_certificate }}"
 nginx['ssl_certificate_key'] = "{{ gitlab_ssl_certificate_key }}"
 
 letsencrypt['enable'] = "{{ gitlab_letsencrypt_enable }}"
-{% if gitlab_letsencrypt %}
+{% if gitlab_letsencrypt_enable %}
 letsencrypt['contact_emails'] = "{{ gitlab_letsencrypt_contact_emails | to_json }}"
 letsencrypt['auto_renew_hour'] = "{{ gitlab_letsencrypt_auto_renew_hour }}"
 letsencrypt['auto_renew_minute'] = "{{ gitlab_letsencrypt_auto_renew_minute }}"