Default the login logo url points to WordPress.org. If you have a custom WordPress login logo, or a completely custom WordPress login page design, then you should probably change the login logo url to your main site or anything that you think is more relevant.
All you have to do is simply paste the codes below in your theme’s functions.php file:
<?php
add_filter( 'login_headerurl', 'custom_logo_url' );
function custom_logo_url($url)
{
return 'http://example.com';
}
?>
