mobimo/support#2982 Configure mailhog when enabled in config

templates/settings.docker.php.twig

@@ -31,7 +31,7 @@ $databases = array(
     ),
   ),
 );
-{% if not drupal.live|default(0) %}
+{% if not drupal.live|default(0) or mailhog.enable %}
 $config['smtp.settings']['smtp_host'] = 'mailhog';
 $config['smtp.settings']['smtp_hostbackup'] = '';
 $config['smtp.settings']['smtp_port'] = '1025';