Update git submodules

Update git submodules

* Update docs/submodules/so.git from branch 'master'
  to f2c39570e2d1f602e72b169ebf796b93d162b3c4
  - Merge "Added AAF SSL certs related changes"
  - Added AAF SSL certs related changes

    Removed client certs from the docker image.
    These client certs will be mounted on the
    docker image using helm charts. This will
    allow helm users to manage AAF credentials
    using the keyfile available in SO OOM
    for CADI AAF feature.

    Issue-ID: SO-2451
    Signed-off-by: Ramesh Parthasarathy(rp6768)<ramesh.parthasarathy@att.com>
    Change-Id: I03efc6ad279f0eaf6773b0ddd42ab43fc053e424