Update git submodules

* Update docs/submodules/fds from branch 'stable/danube'
  - Documentation for odl_l3-fdio-ha scenario

    Change-Id: I21468f8e64e1558640ba216e728e7e230b803f08
    Signed-off-by: Frank Brockners <fbrockne@cisco.com>
    (cherry picked from commit c175886ec8d6f55c3c069f8506c37262cc63009e)

diff --git a/docs/submodules/fds b/docs/submodules/fds
index 942a522..606662e 160000 (submodule)
--- a/docs/submodules/fds
+++ b/docs/submodules/fds
@@ -1 +1 @@
-Subproject commit 942a522ece2a9b016d37a1c475a30db9c3caecb7
+Subproject commit 606662ebc55af621bf62991668cb8a27ea6eb334