Update git submodules

* Update docs/submodules/doctor from branch 'stable/gambia'
  - Local Documentation Builds

    This adds configuration for performing local documentation builds
    with the following simple command:

    tox -e docs

    This patch is part of our documentation effor to Move away from
    submodules
    https://docs.opnfv.org/en/latest/how-to-use-docs/local-build-transition.html

    Your project is now required to have a docs/index.rst so if you are
    missing this file please create it.

    Change-Id: I32a91a4194e4afe98f4c964052e99419b22330ba
    Signed-off-by: Aric Gardner <agardner@linuxfoundation.org>
    (cherry picked from commit 42333625db781f1ae12212ce903df9b5257ff5e4)

  - Updated from global requirements

    Change-Id: I8801985b722f53188489ace43ccf455c5417d5ae
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/doctor b/docs/submodules/doctor
index 61eb392..f81f379 160000 (submodule)
--- a/docs/submodules/doctor
+++ b/docs/submodules/doctor
@@ -1 +1 @@
-Subproject commit 61eb3927ada784cc3dffb5ddd17f66e47871f708
+Subproject commit f81f379cfafb8f18a5ccd7300256e3fdbca1417c