Remove unused code

plugins/enigma/enigma.js

@@ -2,8 +2,6 @@
 
 window.rcmail && rcmail.addEventListener('init', function(evt) {
     if (rcmail.env.task == 'settings') {
-        rcmail.register_command('plugin.enigma', function() { rcmail.goto_url('plugin.enigma') }, true);
-
         if (rcmail.gui_objects.keyslist) {
             rcmail.keys_list = new rcube_list_widget(rcmail.gui_objects.keyslist,
                 {multiselect:true, draggable:false, keyboard:false});