Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "Doctor stable/gambia and opnfv-7.0.0"
  - Doctor stable/gambia and opnfv-7.0.0

    Doctor Gambia release

    Change-Id: Idf90b116d3e697947b3e9a60163243bff79cf181
    Signed-off-by: Tomi Juvonen <tomi.juvonen@nokia.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 358ddec..35f1e50 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 358ddec610610851c5fa67024a80f6788f2724d5
+Subproject commit 35f1e507f5276b63faed797f906da8c21dc4f8e4