Fixup after adaptions

The last argument was removed, we are now calling a different deprecated
version of the ExecuteScriptInIsolatedWorld.

Change-Id: Ie3d351bfdef7ae490cc94362facc12ae96144a34
Reviewed-by: Michal Klocek <michal.klocek@qt.io>
Reviewed-by: Michael Brüning <michael.bruning@qt.io>