Fix the location where the web-extension plugin is installed to be consistent with the primary bakefile-based build system: i.e. to use lib/wx/x.y.z for devel versions and lib/wx/x.y for stable.
Fix the location where the web-extension plugin is installed to be consistent with the primary bakefile-based build system: i.e. to use lib/wx/x.y.z for devel versions and lib/wx/x.y for stable.