Update sample app config file

Author: nirmaoz

samples/photo_album/src/config/config.js.sample

@@ -1,4 +1,4 @@
 export default {
-    cloud_name: 'CCCCCCC',
-    upload_preset: 'UUUUUUUU'
+    cloud_name: 'YOUR_CLOUD_NAME',
+    upload_preset: 'YOUR_UPLOAD_PRESET' //Create an unsigned upload preset and update this
 };