Replacing a this.caseSensitive with self.caseSensitive.

In the `expandBlock` function, `this.caseSensitive` is not set. `self.caseSensitive` (used elsewhere in the function) is set correctly.

This corrects the ILIKE unit test failures described in balderdashy/sails-postgresql#124 (failures 5 & 6). Integration tests for sails-mysql and sails-postgresql both still succeed with this change.