FIX: enable button is broken when color scheme is not saved yet

app/assets/javascripts/admin/models/color_scheme.js

@@ -43,6 +43,10 @@ Discourse.ColorScheme = Discourse.Model.extend(Ember.Copyable, {
     return !this.get('changed') || this.get('saving') || _.any(this.get('colors'), function(c) { return !c.get('valid'); });
   }.property('changed'),
 
+  disableEnable: function() {
+    return !this.get('id') || this.get('saving');
+  }.property('id', 'saving'),
+
   newRecord: function() {
     return (!this.get('id'));
   }.property('id'),

app/assets/javascripts/admin/templates/customize_colors.js.handlebars

@@ -18,7 +18,7 @@
 
         <div class="controls">
           <button {{action save}} {{bind-attr disabled="disableSave"}} class='btn'>{{i18n admin.customize.save}}</button>
-          <button {{action toggleEnabled}} class="btn">
+          <button {{action toggleEnabled}} {{bind-attr disabled="disableEnable"}} class="btn">
             {{#if enabled}}
               {{i18n disable}}
             {{else}}