[devtools] remove the remaining bw compat for old-style tests
It is just:
* dangerously untested right now
* on the path of further bw compat removal (cnxset handling)
webtest drops an apparently pointless .login call
Related to #3933480.
Document: cubicweb-doc
Title: CubicWeb documentation
Author: Logilab
Abstract: Some base documentation for CubicWeb users and developpers
Section: Apps/Programming
Format: HTML
Index: /usr/share/doc/cubicweb-documentation/index.html
Files: /usr/share/doc/cubicweb-documentation/*.html