Removed not needed mountpoint and removed ubuntu section

Referring to BZ#1683290, as dsavineau suggests, being this
bug tripleO specific, removed the ubuntu section and removed
useless mountpoints.

Signed-off-by: fpantano <fpantano@redhat.com>

roles/ceph-rgw/templates/ceph-radosgw.service.j2

@@ -18,10 +18,7 @@ ExecStart=/usr/bin/{{ container_binary }} run --rm --net=host \
   -v /var/run/ceph:/var/run/ceph:z \
   -v /etc/localtime:/etc/localtime:ro \
   {% if ansible_distribution == 'RedHat' -%}
-  -v /etc/pki/ca-trust/extracted:/etc/pki/ca-trust/extracted:ro \
-  -v /etc/pki/ca-trust/source/anchors:/etc/pki/ca-trust/source/anchors:ro \
-  {% elif ansible_distribution == 'Ubuntu' -%}
-  -v /etc/ssl/certs:/etc/ssl/certs:ro \
+  -v /etc/pki/ca-trust/extracted:/etc/pki/ca-trust/extracted:z \
   {% endif -%}
   -e CEPH_DAEMON=RGW \
   -e CLUSTER={{ cluster }} \