Update git submodules

* Update docs/submodules/functest from branch 'master'
  - Fix command in prepare env to execute check_os.sh

    [1] introduced a bug when adding "sh" to the call.
    There is no need to use sh or bash in the command string.

    [1]: https://gerrit.opnfv.org/gerrit/#/c/36163/

    Change-Id: I9ce443721b69945a4a749da0caa6c008cc8ca284
    Signed-off-by: jose.lausuch <jose.lausuch@ericsson.com>

diff --git a/docs/submodules/functest b/docs/submodules/functest
index 28d74e2..4d66967 160000 (submodule)
--- a/docs/submodules/functest
+++ b/docs/submodules/functest
@@ -1 +1 @@
-Subproject commit 28d74e22e5e7a252996c1e0cb29ccb21a97fdeb0
+Subproject commit 4d669670f13e5ab4394a2c9e38073bf7281555ae