Shut up warnings about calling cloneNode() with no parameters

The default value of the parameter is changing, so Firefox warns
when you call cloneNode() with no parameters. Instead, explicitly
call cloneNode( false ).

https://developer.mozilla.org/en-US/docs/Web/API/Node.cloneNode

Change-Id: I817dff372727641c2ff2beda68f7327cb9a8ac19