We removed the "apache" setting for "radosgw_frontend" in
adfdf6871e.
As part of that change, we removed the final references to
ceph-extra.repo, but I failed to clean up this file itself.
Now that nothing uses this file, delete it.
This file contained the sole reference to redhat_distro_ceph_extra, so
we can drop that variable as well.
a397922 introduced a syntax error by attempting to default an unquoted
string, which causes execution failures on some ansible versions with:
Failed to template {{ ceph_rhcs_mount_path }}: Failed to template {{ ceph_stable_rh_storage_mount_path | default(/tmp/rh-storage-mount) }}: template error while templating string: unexpected '/'
Ken Dreyer
Logan V
Guillaume Abrioux