Update git submodules

* Update docs/submodules/releng from branch 'master'
  to e999c69ef480272afe8ee91213bc13891e052082
  - Set a few email-ext attributes

    Change-Id: Ic908b154127644edc589f7eb73a6e07c26ae6321
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 07263f2..e999c69 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 07263f2518201b381254b843f404717a497304b7
+Subproject commit e999c69ef480272afe8ee91213bc13891e052082