Update git submodules

Update git submodules

* Update docs/submodules/oom/offline-installer.git from branch 'master'
  to cf81ff7da21aed314f2dfc74fc6cd04d7354bdf1
  - Merge "Fix issue with yaml.load in docker collector"
  - Fix issue with yaml.load in docker collector

    docker-images-collector.sh script uses yaml.load python function in
    deprecated way and it is a potential security risk

    https://github.com/yaml/pyyaml/wiki/PyYAML-yaml.load(input)-Deprecation

    Issue-ID: OOM-1897

    Change-Id: Ie30e60b4ede2c87a02b7bbe76e0695f91dc207c6
    Signed-off-by: Tomáš Levora <t.levora@partner.samsung.com>