[db dump/restore] fix '#615840: db-dump must be always runnable' by setting repairing on config. Also, avoid to read the whole schema from the database on dump/restore: the bootstrap schema is enough.

"""pre 3.6 bw compat"""
# pylint: disable-msg=W0614,W0401
from warnings import warn
warn('moved to cubicweb.mttransforms', DeprecationWarning, stacklevel=2)
from cubicweb.mttransforms import *