title: Cannot use JSONP with specific url
body: <p>Why i can't use JSONP Store with this url <a href="http://www.sozler.im/rest/categories" rel="nofollow">http://www.sozler.im/rest/categories</a> <br>
  When i am trying on Sencha Architect, right click on Store/Load Data it gives an error, but it works on browser<br>
  Here is the source</p>
  
  <pre><code>Ext.define('SozlerimMobile.store.CategoryStore', {
  extend: 'Ext.data.Store',
  
  requires: [
      'SozlerimMobile.model.Categories',
      'Ext.data.proxy.JsonP',
      'Ext.data.reader.Json'
  ],
  
  config: {
      autoLoad: true,
      autoSync: true,
      model: 'SozlerimMobile.model.Categories',
      storeId: 'CategoryStore',
      proxy: {
          type: 'jsonp',
          extraParams: {
              Status: 'Active'
          },
          url: 'http://www.sozler.im/rest/categories/',
          reader: {
              type: 'json',
              clientIdProperty: 'id',
              idProperty: 'id',
              rootProperty: ''
          }
      }
  }
  </code></pre>
  
  <p>});</p>