fix CLOUDSRV-4204 Upgrading mongodb driver to 1.11.1

# Ticket
https://jira.appcelerator.org/browse/CLOUDSRV-4204

# Description
ACS will upgrade mongo ruby driver, so mongoid need to make some related changes.
I think indent is off by one space.
And maybe we could simplify as `params = [new_hosts, options]`?