[session] don't silently ignore commits commits while in the precommit or postcommit phase are silently ignored. This is OK in precommit since there'll be a commit afterwards anyway; OTOH in postcommit it may surprise the developer who didn't read the documentation for postcommit operations carefully enough. Related to #4383922.

#!/usr/bin/env python
from cubicweb.cwctl import run
import sys
run(sys.argv[1:])