Update git submodules

* Update docs/submodules/functest from branch 'stable/fraser'
  - Protect vs former OS env vars

    rally_jobs is failing vs APEX which still sets OS_TENANT [1].

    [1] https://build.opnfv.org/ci/view/functest/job/functest-apex-baremetal-daily-master/324/console

    Change-Id: I672bfa93b37b1b773ea7d20fdd91bea0ff14b79f
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>
    (cherry picked from commit 83e0e6836d7f5e18eb4eb8c9d28b4e6980b790c2)

  - List default secgroup via orig user

    Else the generated account can be already removed [1].

    [1] https://build.opnfv.org/ci/view/functest/job/functest-apex-baremetal-daily-master/324/console

    Change-Id: I93d88763cdc67cd38286c24ad830244e0c12e019
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>
    (cherry picked from commit f6748c8f3737bf7fbae519319b93e88db9e65834)

  - Conform with OpenStack Pike gates

    It excludes slow tests conforming with OpenStack Gates.
    All tests run in parallel here.

    It should be noted that only one skipped test was in failure here.
    tempest.scenario.test_network_basic_ops.TestNetworkBasicOps.test_mtu_sized_frames

    Change-Id: I110a8cf5dd8603f29f40fcf01fc277d468582bf6
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/functest b/docs/submodules/functest
index 430ca21..6dc2c39 160000 (submodule)
--- a/docs/submodules/functest
+++ b/docs/submodules/functest
@@ -1 +1 @@
-Subproject commit 430ca21da1f52a15491e4ad2acf3eabd16e1e203
+Subproject commit 6dc2c395487d9ae69a6b23b9616d9f28e2de0cbf