Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Apex: fixes snapshot promotion be variables

    Since job names changed during the migration to multijob, we need to
    update the scripts which assume the the snapshot type is part of the job
    name.  Moving them to be jjb variables instead and not rely on job name.

    Change-Id: I18f3bd5488c36b2f82a7bc7cb80045ab6807fa57
    Signed-off-by: Tim Rozet <trozet@redhat.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 8efe448..3c9586d 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 8efe44853121774b32960149e8c8323038235d5b
+Subproject commit 3c9586d2ea6e32940e9fa311de495520d26c719d