Fix extern path

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxPython/trunk@75431 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Adapt to new location and content of pub sub examples

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxPython/trunk@75432 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775