text correction

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

@@ -7,7 +7,7 @@ $wb['dashboard_atom_url_client_txt'] = 'Dashboard atom feed URL (client)';
 $wb["warning"] = 'Edit these values carefully! Do not remove the prefixes on a systems with more then one client.';
 $wb['tab_change_discard_txt'] = 'Discard changes on tab change';
 $wb['tab_change_warning_txt'] = 'Tab change warning';
-$wb['tab_change_warning_note_txt'] = 'Show a warning on tab change in edit forms if any data have been altered by the user.';
+$wb['tab_change_warning_note_txt'] = 'Show a warning on tab change in edit forms if any data has been altered by the user.';
 $wb["dbname_prefix_txt"] = 'Database name prefix';
 $wb["dbuser_prefix_txt"] = 'Database user prefix';
 $wb["shelluser_prefix_txt"] = 'Shell user prefix';