Update git submodules

* Update docs/submodules/releng from branch 'master'
  to 75d515484e188a0cd4772e8acfd8087be9740de2
  - Clean other obsolete jjbs

    They should have been cleant when closing the projects.

    Change-Id: I44ae595201724886fa55f436ed8c7d5b44015775
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 80be2bb..75d5154 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 80be2bbf6021d83002cbb96e116262f0f12e6ebd
+Subproject commit 75d515484e188a0cd4772e8acfd8087be9740de2