Update git submodules

* Update docs/submodules/fuel from branch 'master'
  - Update Host OS NTP Servers to pool.ntp.org

    Old *.fuel.pool.ntp.org values are no longer accessible

    Change-Id: I0879dbd6a262491b4dc9f24d77fb87a007cbaec8
    Signed-off-by: Catalina Focsa <catalina.focsa@enea.com>

diff --git a/docs/submodules/fuel b/docs/submodules/fuel
index 4a360c5..86eaf30 160000 (submodule)
--- a/docs/submodules/fuel
+++ b/docs/submodules/fuel
@@ -1 +1 @@
-Subproject commit 4a360c5076f839c8b700638f9b85c3e630894826
+Subproject commit 86eaf30b6b76d6ca1acbea243d2fdf100df43388