Using radosgw as a drop-in replacement for Swift in openstack-ansible

[vignesh]

the variable name is ceph_conf_overrides: and not ceph_conf_overrides_rgw:

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-----------------------------------
Release: on 2018-10-30 11:37:42
SHA: 55946f15828c7741ec96185d2599722814c151e2
Source: https://opendev.org/openstack/openstack-ansible/src/doc/source/user/ceph/swift.rst
URL: https://docs.openstack.org/openstack-ansible/latest/user/ceph/swift.html

[Dmitriy Rabotyagov (noonedeadpunk)]

We do have variable `ceph_conf_overrides_rgw` which will influence ceph_conf_overrides as a result:
https://opendev.org/openstack/openstack-ansible/src/branch/master/inventory/group_vars/ceph_all.yml#L29