Update git submodules

* Update docs/submodules/armband from branch 'stable/euphrates'
  - u/fuel: Bump & rebase for image pre-install

    1. Bump to latest Fuel@OPNFV to include:
       - Bring in newer glusterfs for mtime unsplit brain
         * Requires adding arch "arm64" to PPA definition in reclass:
           - (reclass-system) linux.system.repo.glusterfs: Add arm64 arch
       - Switch nofeature-ha compute nodes to UCA repo
         * Requires an alternative way of adding linux.enea.com repos;
         * linux.enea.com repos will now be pre-install into VM images;
         * Requires refresh on repo arch list handled by Armband patch:
           - (fuel) baremetal, virtual: Extend arch list for UCA repo

    2. Staging proposed patches from upstream Fuel@OPNFV:
       - Add pre-{install,purge} support for base image
         * Reference implementation adds pre-installed Armband specifics:
           - Enea public GPG to APT keys (for below repos);
           - repos (linux.enea.com/{apt-mk,mcp-repos}/*);
           - linux-{image,headers}-generic-hwe-16.04-edge;
           - cloud-init: datasource from NoCloud only;
         * Allows us to drop kernel installation from state files,
           installing the kernel only once during image prep, instead of
           two stages of parallel installs (5 baremetal, 14 VCP);
         * Ensures Armband repos are pre-configured for infrastructure
           VMs, allowing us to drop more reclass repo definitions;
         * Rework armband patch to install kernel only on kvm, cmp:
           - (fuel) baremetal: linux-image-generic-hwe-16.04-edge

    3. Sync reclass repo definitions with upstream change, drop duplicates
       - [linux][repos] Remove unused repositories [1]
         * Upstream dropped all "ocata-{security,hotfix,...} repo comps,
           which are also empty for Armband, so drop them too;
         * Rework following armband patches:
           - (reclass-system) linux/system/repo/mcp: Add Armband repos
             * Move Armband repos to new dedicated reclass classes:
               - linux.system.repo.mcp.armband.extra (currently empty);
               - linux.system.repo.mcp.armband.openstack;
             * Use HTTPS for fetching Enea Armband GPG key;
           - (fuel) baremetal: Add Armband Openstack repos to kvm, cmp
             * Consume defs introduced above only on baremetal nodes;

    4. Sync documentation with Fuel@OPNFV (cp)

    5. Add vim swap files to .gitignore

    [1] https://github.com/Mirantis/reclass-system-salt-model/commit/1dd1b31

    Change-Id: Ibab56279de86f08ad7cd9bc6761f4c525532f811
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>
    (cherry picked from commit 37083673d6cdddbb9b710f4dd5efe832753e5856)

diff --git a/docs/submodules/armband b/docs/submodules/armband
index 3293d28..b49021e 160000 (submodule)
--- a/docs/submodules/armband
+++ b/docs/submodules/armband
@@ -1 +1 @@
-Subproject commit 3293d28284b3d2d140f3b82452cfb6b16a7f2f2a
+Subproject commit b49021e1227573fbde13c82f432635ef187b1e83