wp dosn;t log in

Hello
I reinstalled my wp site in a new host. and now I have problem with multisite activating. everything is well but when I paste to wp-config the code that wp gives after it the log in process dosent work and it says that the password is incorrect but when i delete thet code from wp-config the login process works.
please guide me , whats the problem. i did everything like tutorial :
define(‘WP_DEBUG’, false);

define(‘WP_ALLOW_MULTISITE’, true);
define( ‘MULTISITE’, true );
define( ‘SUBDOMAIN_INSTALL’, false );
$base = ‘/’;
define( ‘DOMAIN_CURRENT_SITE’, ‘www.qahvegardi.com’ );
define( ‘PATH_CURRENT_SITE’, ‘/’ );
define( ‘SITE_ID_CURRENT_SITE’, 1 );
define( ‘BLOG_ID_CURRENT_SITE’, 1 );
/* That’s all, stop editing! Happy blogging. */