Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Remove snaps testcases in gate

    Snaps is outdated regarding requirements and snaps won't be
    updated.

    Change-Id: Ifa4005f5b26bcdda6347dc169914e7369fd1d4c3
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 19d2985..5a8b24d 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 19d29858d8eac53ed391737bcd602c86b1e3c1a2
+Subproject commit 5a8b24d2ae0c157cfbd0dd2ec0f5d1145e60c46a