Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Apex: Converts machine type for snapshot deploys to 'pc'

    Change-Id: Ic996d49b161af23184fbbce4812c103a158ebef2
    Signed-off-by: Tim Rozet <trozet@redhat.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index f49d86b..4cd8a1e 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit f49d86bbc83fa0a7c38728a2503a970a32f94f88
+Subproject commit 4cd8a1e401e660af7f0f519c8217709650d4515a