Update git submodules

* Update docs/submodules/armband from branch 'master'
  - p/fuel: Bring back glusterfs PPA arch patch

    Fuel@OPNFV bumped glusterfs to 3.13 via glusterfs PPA, so bring
    back our linux.system.repo.glusterfs patch, enabling arm64.

    While at it, paralellize the addition of opnfv user on VCP nodes.

    Change-Id: Ic260c54bed05902fa6e8569ab368d0226850f297
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>

diff --git a/docs/submodules/armband b/docs/submodules/armband
index b54a402..5312ef6 160000 (submodule)
--- a/docs/submodules/armband
+++ b/docs/submodules/armband
@@ -1 +1 @@
-Subproject commit b54a402f6e089aea752987d5139b9030fca7bbc6
+Subproject commit 5312ef6a151a141776856e649a0e7d610b0ad626