fix tab traversal of wxStaticBox children, closes #15376

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74615 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
don't pass false as a wxWindowID

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74616 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775