Vignette fix unit tests

The Last Set Of Fixes, now we should be fine :)

@Wikia/platform-team / @lizlux 

```
1) ServiceTest::testAvatarService
Failed asserting that '<img src="http://vignette.wikia-dev.com/messaging/images/1/19/Avatar.jpg/revision/latest/scale-to-width/20" width="16" height="16" class="avatar" alt="WikiaBot" /> <a href="/wiki/User:WikiaBot">WikiaBot</a>' matches PCRE pattern "/\/20px-/".

/var/lib/jenkins/workspace/phpUnit_trunkUnit/tests/unit/ServiceTest.php:25

2) AvatarServiceTest::testGetAvatarUrl with data set #0 ('/images/thumb/1/19/Avatar.jpg/20px-Avatar.jpg', '80.2.3.4', 0, 20)
Failed asserting that 'http://vignette.wikia-dev.com/messaging/images/1/19/Avatar.jpg/revision/latest/scale-to-width/20' ends with "/images/thumb/1/19/Avatar.jpg/20px-Avatar.jpg".

/var/lib/jenkins/workspace/phpUnit_trunkUnit/includes/wikia/services/tests/AvatarServiceTest.php:65

3) AvatarServiceTest::testGetAvatarUrl with data set #1 ('/images/thumb/e/e1/123456/20px-123456', 'TestUser123', 123456, 20)
Failed asserting that 'http://vignette.wikia-dev.com/messaging/images/e/e1/123456/revision/latest/scale-to-width/20' ends with "/images/thumb/e/e1/123456/20px-123456".

/var/lib/jenkins/workspace/phpUnit_trunkUnit/includes/wikia/services/tests/AvatarServiceTest.php:65
```