cdn-img will render nothing if src is null

app/assets/javascripts/discourse/components/cdn-img.js.es6

@@ -1,8 +1,10 @@
-export default Ember.Component.extend({
+import computed from 'ember-addons/ember-computed-decorators';
-  tagName: 'img',
-  attributeBindings: ['cdnSrc:src'],
 
-  cdnSrc: function() {
+export default Ember.Component.extend({
-    return Discourse.getURLWithCDN(this.get('src'));
+  tagName: '',
-  }.property('src')
+
+  @computed('src')
+  cdnSrc(src) {
+    return Discourse.getURLWithCDN(src);
+  }
 });

app/assets/javascripts/discourse/templates/components/cdn-img.hbs

@@ -0,0 +1,3 @@
+{{#if src}}
+  <img src={{cdnSrc}} class={{class}}>
+{{/if}}