Update git submodules

* Update docs/submodules/armband from branch 'master'
  - p/fuel: Retire OPNFV user

    Now that networking configuration is stable and we rarely run into
    serial-only access situations, it is safe to retire the OPNFV user.

    While at it, bump Fuel@OPNFV git submodule to pick up minor updates.

    Change-Id: I233e054795592700b7ec7e7031e1c2c9b8cc3450
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>

diff --git a/docs/submodules/armband b/docs/submodules/armband
index d6ff3a1..73161ee 160000 (submodule)
--- a/docs/submodules/armband
+++ b/docs/submodules/armband
@@ -1 +1 @@
-Subproject commit d6ff3a19ef707db95e38589598c5fcbc194d6032
+Subproject commit 73161ee4be1766447a1f54e122f857caef307c8a