remove mailbox_limit from README

README.md

@@ -135,7 +135,6 @@ At first the database access has to be configured.
 	define("DBC_USERS_USERNAME", "username");
 	define("DBC_USERS_DOMAIN", "domain");
 	define("DBC_USERS_PASSWORD", "password");
-	define("DBC_USERS_MAILBOXLIMIT", "mailbox_limit");
 	
 	// Domains table columns
 	define("DBC_DOMAINS_ID", "id");