remove unused file

interface/web/admin/lib/lang/es_syslog_list.lng

-<?php
-$wb['list_head_txt'] = 'ISPConfig Log';
-$wb['tstamp_txt'] = 'Date';
-$wb['server_id_txt'] = 'Server';
-$wb['loglevel_txt'] = 'Loglevel';
-$wb['message_txt'] = 'Message';
-?>