add this Wp-config for plugun delete and add permission:

define('FS_METHOD', 'direct');
define('FTP_BASE', '/var/www/http://localhost/drupalpartners/');
define('FTP_CONTENT_DIR', '/var/www/http://localhost/drupalpartners/wp-content/');
define('FTP_PLUGIN_DIR ', '/var/www/http://localhost/drupalpartners/wp-content/plugins/');