Updated to use a matching expression instead.

Replaced the booleans with a matching expression. Now, URLs
beginning with the following patterns will be ignored:

- blob:
- data:
- http://
- https://
- //

As suggested by @pnstickne.

Author: rblopes

src/loader/Loader.js

@@ -2028,7 +2028,7 @@ Phaser.Loader.prototype = {
             return false;
         }
 
-        if (url.substr(0, 5) === 'data:' || url.substr(0, 4) === 'http' || url.substr(0, 2) === '//')
+        if (url.match(/^(?:blob:|data:|http:\/\/|https:\/\/|\/\/)/))
         {
             return url;
         }