Update git submodules

* Update docs/submodules/apex from branch 'stable/danube'
  - nosdn fdio scenario fixes

    - pins nosdn fdio packages that work
    - disable l3 agent ha mode

    opnfv-tht-pr: 130

    Change-Id: I9470565768611f83cbd6e34f567a0aec58fa65ef
    Signed-off-by: Tim Rozet <trozet@redhat.com>
    Signed-off-by: Feng Pan <fpan@redhat.com>
    (cherry picked from commit 778593a0d93f1a994c58a30c2dfc3f2243bf1b2f)

diff --git a/docs/submodules/apex b/docs/submodules/apex
index 1a10b8e..d5a8930 160000 (submodule)
--- a/docs/submodules/apex
+++ b/docs/submodules/apex
@@ -1 +1 @@
-Subproject commit 1a10b8e7559ca75f5ac624d561303cf20bac9bc9
+Subproject commit d5a893088b4965806ae81dbc08ba2bf9da23a72e