[server] Drop inexistent "bootstrap" argument in Repository initialization This is a missing bit from 5de78b6fff2e. Unfortunately this code appears to be uncovered by our test suite.

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