Update templates/mailhost/mailhost_ssl_settings.epp

Co-authored-by: Tim Meusel <tim@bastelfreak.de>

Author: sebastianrakel

templates/mailhost/mailhost_ssl_settings.epp

@@ -7,7 +7,7 @@
   Optional[String] $ssl_ecdh_curve,
   Optional[String] $ssl_key,
   Optional[String] $ssl_password_file,
-  Optional[Enum['on', 'off']] $ssl_prefer_server_ciphers,
+  Enum['on', 'off'] $ssl_prefer_server_ciphers,
   Optional[String] $ssl_protocols,
   Optional[String] $ssl_session_cache,
   Optional[String] $ssl_session_ticket_key,