Update git submodules

* Update docs/submodules/fuel from branch 'master'
  - [virtual/odl] Use default gw offered from dhcp

    Remove default route to external gateway on compute nodes
    instead of placing wrapper script as a workaround.

    Change-Id: I8e1d5d9920a7aa2ed2d1092ebce692176a3bf41a
    Signed-off-by: Michael Polenchuk <mpolenchuk@mirantis.com>

diff --git a/docs/submodules/fuel b/docs/submodules/fuel
index f74f7ba..ab97b5d 160000 (submodule)
--- a/docs/submodules/fuel
+++ b/docs/submodules/fuel
@@ -1 +1 @@
-Subproject commit f74f7bac151f69ae0b50f28e68805a5d8580736e
+Subproject commit ab97b5dff595d0e342a0121310a9c2e42f502bb4