Remove confusing conditions in where-clause

It seems that I was wrong in issue #9. The possible items are selected in the find above, the AND statement here is useless and therefore I removed the confusing statement.

I've also changed the CakePHP branch version to 2.6 since the 2.5 branch doesn't exist anymore.
You are missing the App::uses() for it at the top.
If you add this I will merge immediately.