[GH-555] Failing test case for iterable ObjectHydrator

This issue is created automatically through a Github pull request on behalf of everzet:

Url: https://github.com/doctrine/doctrine2/pull/555

Message:

Here's the deal, whether you're using `ObjectHydrator::iterate()` on query with scalars, on each consequent iteration scalars go into advanced subarray. In terms of failing test case, we're getting:

```

• iteration #1
  array(1)
  Unknown macro: { [0]=> array(2) { ["id"]=> string(1) "1" ["name"]=> string(6) "romanb" }
  }
  - iteration #2
  array(1) {
  [1]=> array(2) { ["id"]=> string(1) "2" ["name"]=> string(5) "jwage" }
  }
  - iteration #3
  array(1) {
  [2]=> array(2) { ["id"]=> string(1) "3" ["name"]=> string(7) "everzet" }
  }
  ```
  
  Where in reality we expect:
  
  ```
  - iteration #1
  array(1) {
  [0]=> array(2) { ["id"]=> string(1) "1" ["name"]=> string(6) "romanb" } }
• iteration #2
  array(1)
  Unknown macro: { [0]=> array(2) { ["id"]=> string(1) "2" ["name"]=> string(5) "jwage" } }
• iteration #3
  array(1)
  Unknown macro: { [0]=> array(2) { ["id"]=> string(1) "3" ["name"]=> string(7) "everzet" } }

  ```