Update git submodules

* Update docs/submodules/clover from branch 'stable/fraser'
  - Merge "Create index to be included in opnfvdocs site" into stable/fraser
  - Create index to be included in opnfvdocs site

    Change-Id: Icbfe547697a8d879f4af8d9f9fbde2211b63129c
    Signed-off-by: Yujun Zhang <zhang.yujunz@zte.com.cn>
    (cherry picked from commit 406b5d7a74569510aa687882af98024d0e74bc7a)

diff --git a/docs/submodules/clover b/docs/submodules/clover
index 0898217..ffd7c93 160000 (submodule)
--- a/docs/submodules/clover
+++ b/docs/submodules/clover
@@ -1 +1 @@
-Subproject commit 08982178d1f9c0c17b24488a7b56049a5ae335b8
+Subproject commit ffd7c93b70144f412cd90601646730a2773c2ea3