Update git submodules

* Update docs/submodules/clover from branch 'master'
  - Initial commit for monitoring by prometheus

    - install prometheus
    - validate the installation
    - add prometheus query function
    - TODO: test collecting telemetry data from istio

    JIRA: CLOVER-7

    Change-Id: I983be2db78c8c5c20c0acee9ae81e891884e07fb
    Signed-off-by: QiLiang <liangqi1@huawei.com>

diff --git a/docs/submodules/clover b/docs/submodules/clover
index 9f3d87d..9423f2e 160000 (submodule)
--- a/docs/submodules/clover
+++ b/docs/submodules/clover
@@ -1 +1 @@
-Subproject commit 9f3d87d798cf04c243e82d284a7dc4f7b3ec5c1a
+Subproject commit 9423f2e5911a9933744e827c9b09e2e9025b4aee