Update git submodules

* Update docs/submodules/functest from branch 'master'
  - Remove opnfv/functest-restapi

    REST api server should run on top of all Functest containers by
    overriding the default command.

    We can safely remove it and meet the Docker Slicing approach.

    Change-Id: Ibcc56490c931ae701bd31c52650081a115183e22
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/functest b/docs/submodules/functest
index 1ca8548..aca4e83 160000 (submodule)
--- a/docs/submodules/functest
+++ b/docs/submodules/functest
@@ -1 +1 @@
-Subproject commit 1ca85485f74d09dfd6787b75fb40cb70dce64e4b
+Subproject commit aca4e83931aa48b633cbb399bd4e9f16d3acdb13