Update git submodules

* Update docs/submodules/doctor from branch 'master'
  - Updates upstream file (dataplane status to network port in Neutron)

    Change-Id: I00f232dede044ca396fe914272e7ade9ac9d6753
    Signed-off-by: Bertrand Souville <souville@docomolab-euro.com>

diff --git a/docs/submodules/doctor b/docs/submodules/doctor
index 7e0ab6e..3a6fc64 160000 (submodule)
--- a/docs/submodules/doctor
+++ b/docs/submodules/doctor
@@ -1 +1 @@
-Subproject commit 7e0ab6e2149df22455e58eb363eb291a985514de
+Subproject commit 3a6fc64c8f2eefa3d988bd624d23e3f22a92ea90