Update git submodules

* Update docs/submodules/apex from branch 'master'
  - Update queens ODL to include OF table fix

    Also includes minor fix to patching where stable was not being removed
    from the short hand branch name correctly.

    Includes fix where path was changed in queens for env files:
    https://review.openstack.org/#/c/567810/

    Change-Id: Ia3a6769be70ea97c9bec9d5539c9ab0373fed30a
    Signed-off-by: Tim Rozet <trozet@redhat.com>

diff --git a/docs/submodules/apex b/docs/submodules/apex
index b5e2f1f..6b9d8c0 160000 (submodule)
--- a/docs/submodules/apex
+++ b/docs/submodules/apex
@@ -1 +1 @@
-Subproject commit b5e2f1f65dee0cd692fe275d6bce69a8e410cac3
+Subproject commit 6b9d8c01be763bbf46048caa08902880367672a7