Update git submodules

Update git submodules

* Update docs/submodules/releng-xci from branch 'master'
  - Enable running on CentOS/RedHat family

    Changes that make it possible to run XCI on CentOS:

    - Remove the check on xci-deploy.sh script that exists on RedHat family
    (including CentOS) and making the error into a warning.
    - Add centos to a distro in opnfv-scenario-requirements

    Change-Id: Ief6f1e50d8c7c9d8787641827e57682a6e0549e4
    Signed-off-by: Tapio Tallgren <tapio.tallgren@nokia.com>
  - Create CentOS networking configuration

    Change-Id: If8c0de44c313fdc22b1c7443b12d42769035c5b0
    Signed-off-by: Tapio Tallgren <tapio.tallgren@nokia.com>
  - Rename centos.yml to redhat.yml in configure-nfs/vars

    'redhat' as a ansible_os_family covers both the RedHat distros and
    CentOS.

    Change-Id: I2ab56024d2c0f1f40a014a236cfd94ef38daad04
    Signed-off-by: Tapio Tallgren <tapio.tallgren@nokia.com>
  - Bump OSA-galera_server SHA to fix a CentOS issue

    Galera installation in CentOS fails because the mysqld.sock file is in a
    different location, despite what the my.cnf configuration tells. This
    has been worked around in upstream OSA-galera_server:

    https://git.openstack.org/cgit/openstack/openstack-ansible-galera_server/
    commit/?id=f2bfbd38513ac8d61ba4e02a4d5ef6cbbca259cc

    Change-Id: Ied11571189eff8cbab0f1990a7599b51cad9ea2b
    Signed-off-by: Tapio Tallgren <tapio.tallgren@nokia.com>