The Gevent worker has specifc needs in term of maximum concurrent
connections to the database and those needs are not compatible with the
default limit that is primerly set for http workers.
This PR makes it possible to supply a configuration dedicated to the
gevent worker.
task-id-3193565
task-id-2146565
closesodoo/odoo#125190
Signed-off-by: Julien Castiaux (juc) <juc@odoo.com>