Do not filter SSL_CERT_REQS to solve an issue with Cron Schedulers

[Thobro]

Hi there!

This change fixes the following issue I had related to the new CronSchedulers.

Because I'm on Heroku I have to set SSL_CERT_REQS to None

RQ_QUEUES = {
    'default': {
        'URL': get_secret('REDIS_URL') + '/1',
        'SSL_CERT_REQS': None
    },
}

However when I acces /admin/django-rq/ I noticed that my list of Cron Schedulers is empty. Some digging led me to the function utils.get_cron_schedulers. This function fails because of [SSL: CERTIFICATE_VERIFY_FAILED]. Looking into the connection I noticed that ssl_cert_reqs=required was in there. This was strange I thought. Digging some more led me to the function connection_utils.filter_connection_params that filtered out my SSL_CERT_REQS setting. When I add SSL_CERT_REQS to the whitelist it all works as expected and I can see my running scheduler on the Cron Schedulers overview on admin/django-rq/.

[selwin]

Thanks!