only set native window level, when not using a wrapped native window, see #14739

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74075 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
fixes potential crash under gatekeeper

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74076 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775