Update git submodules

* Update docs/submodules/apex from branch 'master'
  - Fixes ctlplane default route

    Default route was using the undercloud IP, and instead should be using
    the gateway set for the network in network settings.

    JIRA: APEX-597

    Change-Id: Iff6b18a6553af98cf9da72c278f358922d489958
    Signed-off-by: Tim Rozet <trozet@redhat.com>

diff --git a/docs/submodules/apex b/docs/submodules/apex
index d2913d4..96d6db2 160000 (submodule)
--- a/docs/submodules/apex
+++ b/docs/submodules/apex
@@ -1 +1 @@
-Subproject commit d2913d4bcc0fcd25dc3d01f6604049dfd0a9217d
+Subproject commit 96d6db26ad1f31ef5790e5cc0904361712598c77