Update git submodules

* Update docs/submodules/fuel from branch 'master'
  - [noha] Align MTU settings

    * shift MTU from public bridge to physical interface
    * add neutron related settings

    Change-Id: Ia57d1ca7976968d6e7ee23f58a0abae1a1a256c0
    Signed-off-by: Michael Polenchuk <mpolenchuk@mirantis.com>

diff --git a/docs/submodules/fuel b/docs/submodules/fuel
index 86dcebf..8bb79e6 160000 (submodule)
--- a/docs/submodules/fuel
+++ b/docs/submodules/fuel
@@ -1 +1 @@
-Subproject commit 86dcebf4b39ff2e6b2d28691b308a571177e16a5
+Subproject commit 8bb79e6beb10738d2756d8b33950452bcc44f493