[etwist] Drop try/except around definitions of 'all-in-one' configuration and command handlers cubicweb.server is no longer conditionally shipped, neither in python package nor in debian package since 3.24.

pytest
http://hg.logilab.org/master/logilab/common/archive/default.tar.bz2#egg=logilab-common
http://hg.logilab.org/master/yams/archive/default.tar.bz2#egg=yams