Update git submodules

* Update docs/submodules/fuel from branch 'master'
  - [queens] Update Gnocchi version

    Change-Id: Ieea2c510ae4c6d4db0667f3341c877042a2c1846
    Signed-off-by: Michael Polenchuk <mpolenchuk@mirantis.com>

diff --git a/docs/submodules/fuel b/docs/submodules/fuel
index 33c017d..7d16945 160000 (submodule)
--- a/docs/submodules/fuel
+++ b/docs/submodules/fuel
@@ -1 +1 @@
-Subproject commit 33c017d388bf0f9cef5199c186bec5b4fd01f767
+Subproject commit 7d16945d42ff8744b00d1bd87ab20df914afb06b