Use HTTPS for labs resource

src/frontend/scenes/test.js

@@ -14,7 +14,7 @@
  */
 
 function preload () {
-  this.load.image('404', 'http://labs.phaser.io/assets/sprites/phaser3-logo.png')
+  this.load.image('404', 'https://labs.phaser.io/assets/sprites/phaser3-logo.png')
 }
 function create () {
   this.add.image(300, 400, '404')