Update git submodules

* Update docs/submodules/functest from branch 'master'
  - Merge "Rename IMG_PROP to IMAGE_PROPERTIES"
  - Rename IMG_PROP to IMAGE_PROPERTIES

    Any other env vars are reduced.

    Change-Id: Ic2c37d6efd543603a2495f9d2621b66d61710a54
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/functest b/docs/submodules/functest
index 6b0fa7e..427547d 160000 (submodule)
--- a/docs/submodules/functest
+++ b/docs/submodules/functest
@@ -1 +1 @@
-Subproject commit 6b0fa7ecb5aa0c0dead1d16c2811f5c47347a091
+Subproject commit 427547d5680878dabfa1e8d1e53fdb2921fd01ab