Update git submodules

* Update docs/submodules/container4nfv from branch 'master'
  - Update bookinfo application deploy and clean scripts for Istio 1.0.x

    Since Istio 1.0, a new traffic management API, a.k.a. v1alpha3, is being introduced.
    And there are also some minor changes in the deployment and clean steps for bookinfo application.

    Change-Id: I96c9eb552104dfdce15b4628b29c7cc72ac207b2
    Signed-off-by: JingLu5 <lvjing5@huawei.com>

diff --git a/docs/submodules/container4nfv b/docs/submodules/container4nfv
index 886c8e7..0528b9a 160000 (submodule)
--- a/docs/submodules/container4nfv
+++ b/docs/submodules/container4nfv
@@ -1 +1 @@
-Subproject commit 886c8e7f8ac29d72d073c72e41f386b09ad69dbf
+Subproject commit 0528b9a9bac18a3b6d700467def3318fd53bf22c