Impacted versions:
9.0, 10.0, 11.0 (Maybe 8.0)
I don't know if it is really an expected behaviour for odoo but I like to expose it

Steps to reproduce:

1. Open an ir.cron record and change it to:
 - interval: minutes
 - next execution date: now + 1 minute

2. Open the odoo server log

Note: I'm using workers=3 but I don't know if there is possible to reproduce it without workers.

Current behavior:

You will see for each cron execution the following output
```txt
...
2018-06-01 16:18:33,432 20686 INFO 333561-11-0-42aff9-all odoo.modules.registry: Invalidating all model caches after database signaling.
...
2018-06-01 16:17:21,527 20687 INFO 333561-11-0-42aff9-all odoo.modules.loading: loading 1 modules...
2018-06-01 16:17:21,535 20687 INFO 333561-11-0-42aff9-all odoo.modules.loading: 1 modules loaded in 0.01s, 0 queries
2018-06-01 16:17:21,594 20687 INFO 333561-11-0-42aff9-all odoo.modules.loading: loading 206 modules...
2018-06-01 16:17:21,718 20687 INFO 333561-11-0-42aff9-all odoo.modules.loading: 206 modules loaded in 0.12s, 0 queries
2018-06-01 16:17:21,989 20687 INFO 333561-11-0-42aff9-all odoo.modules.loading: Modules loaded.
```

Expected behavior:
 - Review if the method that run from the cron really requires a invalidate cache and delete all registries.
 - Disable "minutes" for cron interval because all cache are deleted then is not valid use them.

Video/Screenshot link (optional):

 - [![IMAGE ALT TEXT HERE](https://img.youtube.com/vi/Be4FIeQjgjk/0.jpg)](https://youtu.be/Be4FIeQjgjk)
import gevent
        from gevent.wsgi import WSGIServer
        if os.name == 'posix':
            signal.signal(signal.SIGQUIT, dumpstacks)
            signal.signal(signal.SIGUSR1, log_ormcache_stats)
        gevent.spawn(self.watch_parent)
        self.httpd = WSGIServer((self.interface, self.port), self.app)
        _logger.info('Evented Service (longpolling) running on %s:%s', self.interface, self.port)
        try:
            self.httpd.serve_forever()
        except:
            _logger.exception("Evented Service (longpolling): uncaught error during main loop")
            raise
    def stop(self):
        import gevent
        self.httpd.stop()
        gevent.shutdown()
    def run(self, preload, stop):
        self.start()
        self.stop()
class PreforkServer(CommonServer):
    """ Multiprocessing inspired by (g)unicorn.
    PreforkServer (aka Multicorn) currently uses accept(2) as dispatching
    method between workers but we plan to replace it by a more intelligent
    dispatcher to will parse the first HTTP request line.
    """
    def __init__(self, app):