Update git submodules

* Update docs/submodules/apex from branch 'master'
  - Merge "Use stable/17.10 branch for VPP"
  - Use stable/17.10 branch for VPP

    also add retry and timeout for VPP interface check in os-net-config

    apex-os-net-config: Idaf03d78d2ce657ac484c1285a795d98760d0112

    Change-Id: I3dca43d263923e2ae7ff84781d3f7aa64fad6b5d
    Signed-off-by: Feng Pan <fpan@redhat.com>

diff --git a/docs/submodules/apex b/docs/submodules/apex
index f941e23..325ac9a 160000 (submodule)
--- a/docs/submodules/apex
+++ b/docs/submodules/apex
@@ -1 +1 @@
-Subproject commit f941e233e575821695dc876c9a7a9f6c31e6dd00
+Subproject commit 325ac9a9d4582175b513219a45e08947e79599a9