Update git submodules

* Update docs/submodules/functest from branch 'stable/euphrates'
  - Merge "Precise the right Docker tags" into stable/euphrates
  - Precise the right Docker tags

    It updates configguide.rst and runfunctest.rst.

    Change-Id: I48aab7cbfcd8ea6f6da61eef426754f018820cf3
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/functest b/docs/submodules/functest
index f01fdd8..5268d9e 160000 (submodule)
--- a/docs/submodules/functest
+++ b/docs/submodules/functest
@@ -1 +1 @@
-Subproject commit f01fdd86ebfcd8c6c9b368968c2e3572f702b27c
+Subproject commit 5268d9ee0c42994f0ebc96327db6f8d41ae06fe6