Fix the (somewhat specific/rare) case of an exception being thrown when ...

[zytzagoo]

...trying to close the banner by using a more robust approach for referencing the nodes that are removed.

Exceptions occur when our cookiebanner div (and/or mask) is moved within the DOM (for whatever reason) between being injected and being closed/removed.

Legit reasons include certain jQuery plugins for mobile navigation or similar...

[senko]

Thanks!