[repo] ensure we don't restart a task while the repo is shutting down (closes #1942736)
we need a safety belt in cw itself again looping task which use 'try / except'
or doesn't need to access the db (which will trigger ShuttingDown exception)
if versions_map['cubicweb'][0] == (3, 7, 4):
config['http-session-time'] *= 60
config['cleanup-session-time'] *= 60
config['cleanup-anonymous-session-time'] *= 60