Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Apex: Fix functest docker tag in gate job

    Fixes passing quotes as the value for the variable, so now what is
    passed is just an empty string.

    Change-Id: I9abb681374934fe4cf7c8024118278674880f7e9
    Signed-off-by: Tim Rozet <trozet@redhat.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 5f24ca3..d6f2259 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 5f24ca33eae00da304d5a5ba2c023011128dfc7a
+Subproject commit d6f22598dbe1c3174d7f4c894f9bef152cdfe82b