Fix N1ql Classname Typo in fromString Call

Noticed that when trying to use the `fromString()` method, as documented on the [Couchbase Site](http://docs.couchbase.com/developer/php-2.0/n1ql-queries.html), that it tries to insantiate the wrong type of class. This should fix that.

Side note: N1ql is pretty annoying to type.