Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Apex: Fix fluorine name and patch netvirt reinstall

    Temporarily pull in specific patch to fix ODL netvirt reinstall.

    Change-Id: Id3ba00592e81ee0970075b34afb72f76db02d0b4
    Signed-off-by: Tim Rozet <trozet@redhat.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index ea6bc61..c1c6da4 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit ea6bc61f16d7fcbf1b6d33269d690fa349722d61
+Subproject commit c1c6da438037580c8d4d3a85d7b93748d6c7ce3e