[test] Update webconfig's tests accounting for cubicweb-file being now a package WebconfigTC.test_locate_all_files and WebconfigTC.test_locate_resource assumed that cubicweb-file was installed in <share>/cubes/file whereas, from the latest release, it is now a standard Python package thus installed in site-packages as cubicweb_file. We simply update base directory of these two tests.

etc/init.d
etc/cubicweb.d
etc/bash_completion.d
usr/bin
usr/share/doc/cubicweb-ctl
var/log/cubicweb
var/lib/cubicweb/backup
var/lib/cubicweb/instances