Update git submodules

* Update docs/submodules/compass4nfv from branch 'stable/euphrates'
  - Support the scenario for installing kubernetes in ubuntu system

    JIRA: -

    Currently we only support the the scenario for installing kubernetes
    in centos system. This patch is to install kubernetes in ubuntu system

    Change-Id: Idc5eafea5d02c28c62a31e4c29451b8c5aaf1fd5
    Signed-off-by: hu xinhui <xinhui_hu@foxmail.com>
    (cherry picked from commit a9f6a2b1665a31bbdaf266c333410bde2418cf15)

diff --git a/docs/submodules/compass4nfv b/docs/submodules/compass4nfv
index 870460b..8a50c8b 160000 (submodule)
--- a/docs/submodules/compass4nfv
+++ b/docs/submodules/compass4nfv
@@ -1 +1 @@
-Subproject commit 870460bc580ce2bd7e2d0c752c211e8413800c74
+Subproject commit 8a50c8b9bfc532494eb89641cee000dd60f8c0f9