[server/test] use server config in migration
This allows a lighter initialisation (no rtag needed).
Execution of those test move from 300 secondes to 220 seconds here. A 25%
speedup
#! /bin/sh -ecase "$1" in remove) if [ -x "/etc/init.d/cubicweb-ctl" ]; then invoke-rc.d cubicweb-ctl stop || true fi ;;esac#DEBHELPER#exit 0