[cubicweb-ctl] i18ncube return 2 (failed command) on failure (closes #2192336) i18ncube command previously returned 0 even on failure. Bisect i18n breakage was hard.

addressbook
basket
blog
book
calendar
comment
company
email
file
folder
i18ncontent
keyword
link
mailinglist
person
tag
timeseries
vcsfile