Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "fuel-deploy.sh: Fix unbound variable for stable/E"
  - fuel-deploy.sh: Fix unbound variable for stable/E

    Change-Id: I5a8f02944e346319d6c5d4fca10ddc54503e82d7
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index f7d8f8a..af0996b 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit f7d8f8a8b885b2892c7328b7e9a31842b0e925d8
+Subproject commit af0996b10798f9b648c098d3afc5c3d999b7e235