Fix bug with NPE

[gtors]

NullPointerException is raised If at least one item in constrained collection is null.

@Validateable
class SomeCommand {
    List<SubCommand> items
    static constraints = {
         items cascade: true
    }
}

new SomeCommand(items: [null]).validate() // NPE thrown, because `null`  does not have a `class` field

[rmorrise]

I have published 0.1.5 version of the plugin for Grails 2. Sorry for the delay. Can you please verify it?

Thanks!

[gtors]

Sure. I have successfully updated plugin up to 0.1.5 version and checking for null is present.