Update git submodules

* Update docs/submodules/fuel from branch 'master'
  - Configure neutron gateway

    Change-Id: I01744bd5728d6fc4c8cd3792aee9759434d18645
    Signed-off-by: Michael Polenchuk <mpolenchuk@mirantis.com>

diff --git a/docs/submodules/fuel b/docs/submodules/fuel
index 14bfaca..f021e69 160000 (submodule)
--- a/docs/submodules/fuel
+++ b/docs/submodules/fuel
@@ -1 +1 @@
-Subproject commit 14bfaca0fd98995feae9e46a71ccdc227c908ce4
+Subproject commit f021e694f6cae29d245f8455daad8d608d6af1ae