Update git submodules

* Update docs/submodules/functest from branch 'master'
  - Read the env file only if exists

    Change-Id: I8e718e583a5a47a089755c31e623a44732e5ba1e
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/functest b/docs/submodules/functest
index 6432b7d..6fc64d9 160000 (submodule)
--- a/docs/submodules/functest
+++ b/docs/submodules/functest
@@ -1 +1 @@
-Subproject commit 6432b7db47fe05f8b5b4c55d658537bf71a881c6
+Subproject commit 6fc64d9e03d3e34a55c2792fa2e80c1b9a4b93a0