Update git submodules

* Update docs/submodules/apex from branch 'master'
  - Restarts libvirtd after stopping firewalld

    When stopping firewalld, libvirtd needs to be restarted in order for
    libvirt to use/populate iptables with the NAT rules for the default
    virsh network.

    JIRA: APEX-510

    Change-Id: Ia5b4515fd961baa70de58814e9eae4b397db28a7
    Signed-off-by: Tim Rozet <trozet@redhat.com>

diff --git a/docs/submodules/apex b/docs/submodules/apex
index 9ad2cd9..23be56d 160000 (submodule)
--- a/docs/submodules/apex
+++ b/docs/submodules/apex
@@ -1 +1 @@
-Subproject commit 9ad2cd95cb811855cd6dbaf4789d9326ddd5b9b4
+Subproject commit 23be56d9f0801cbc065accf77a850bcc106c1e84