Update git submodules

Update git submodules

* Update docs/submodules/oom/offline-installer.git from branch 'master'
  to d76d4e5948969fe0266645df7e06f973fdb9b44b
  - Merge "Adding versions for infra related docker images"
  - Adding versions for infra related docker images

    1. latest tag replaced by version number for vnc server
    2. added specific version for own_nginx image
    3. version control improved in ansible roles accordingly

    Solves OOM-1766

    Issue-ID: OOM-1767

    Change-Id: I147c56b46a419188099d8ed3e78fed68810893e2
    Signed-off-by: Tomáš Levora <t.levora@partner.samsung.com>