Update git submodules

* Update docs/submodules/releng from branch 'master'
  to 21fad69b5a67fced68aa9c7d51923df74f28ee0b
  - Disable CNTT jobs

    They are blocked due to missing agents.
    Disabling them would avoid lots of manual actions to clean them.

    Change-Id: Idc817ae304707c26ae7312dbd19f6578303e36fa
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 7e1a3cd..21fad69 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 7e1a3cd427ddcd0937369610fba80907c0d5824a
+Subproject commit 21fad69b5a67fced68aa9c7d51923df74f28ee0b