Update git submodules

* Update docs/submodules/bottlenecks from branch 'stable/fraser'
  - Update Dockerfile

    1. Openstack command lines keep poping up warnings which
    cause reading comand results wrongly.
    2. Update the ubuntu version and packages to remove redundance
    which is a historical debt.

    Change-Id: I3cdb7a9ec3f0bc41ecfe5b8bf9d44878485de40f
    Signed-off-by: Yang (Gabriel) Yu <Gabriel.yuyang@huawei.com>
    (cherry picked from commit 0ea5233caabae215afb0769194a87f32a430fa2d)

diff --git a/docs/submodules/bottlenecks b/docs/submodules/bottlenecks
index ca52dc0..6cc8816 160000 (submodule)
--- a/docs/submodules/bottlenecks
+++ b/docs/submodules/bottlenecks
@@ -1 +1 @@
-Subproject commit ca52dc03db2d8530ed149a98ecc1213f9c45ebba
+Subproject commit 6cc88168430565cea5eb7dd278d849947ed1d20d