Nginx ignores HTTP Authentication for WordPress login directory

Solution:

The problem was that the old location block does not pass the PHP configuration to the new block, so that PHP requests are not processed. The following solved this problem:

location ~* /wp-login.php {
            auth_basic "Restricted Area";
            auth_basic_user_file PATH TO .htpasswd;

            try_files $uri =404;
            fastcgi_pass unix:/var/run/php5-fpm.sock;
            fastcgi_index index.php;
            fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
            include fastcgi_params;
    }