Update git submodules

* Update docs/submodules/functest from branch 'stable/gambia'
  - Move tempest logics in tempest_conf.yaml

    It allows removing OPNFV logics out of Functest (releng) and then
    simplifies conf_utils.

    tempest.conf is filled by the current default values.

    functest-alpine.sh will be updated to allow modifying the default
    values without breaking the OPNFV installers.

    It deprecates the only tempest-related env var (STORAGE_PROTOCOL)

    Change-Id: I14bcb715826ef2d85af87e7af600261a3c08e72c
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>
    (cherry picked from commit 3872290bb673513459588bbe83e65efc631615f7)

diff --git a/docs/submodules/functest b/docs/submodules/functest
index 7e897b2..b7f9b53 160000 (submodule)
--- a/docs/submodules/functest
+++ b/docs/submodules/functest
@@ -1 +1 @@
-Subproject commit 7e897b2dc054a6a3700ad20b470f4c2985cea8ae
+Subproject commit b7f9b53a34cd8ffcc9df4d2f286e55e13adb4a58