Update git submodules

* Update docs/submodules/apex from branch 'master'
  - Fix RPM build

    networking-vpp was referencing variables from the old variables.sh.
    Moving those values into the Makefile as the variables.sh file was
    removed.

    Change-Id: I8ef5e6988299e7e3855d442657db2ed20086689f
    Signed-off-by: Tim Rozet <trozet@redhat.com>

diff --git a/docs/submodules/apex b/docs/submodules/apex
index 96d6db2..dc55f3a 160000 (submodule)
--- a/docs/submodules/apex
+++ b/docs/submodules/apex
@@ -1 +1 @@
-Subproject commit 96d6db26ad1f31ef5790e5cc0904361712598c77
+Subproject commit dc55f3a5bc343802bc60cd901ef8adcbafd3fe33