Update git submodules

* Update docs/submodules/netready from branch 'stable/danube'
  - Added details to the installation instructions

    Change-Id: I311e8c7c1d559f6267b194bb55e7fb99c4555635
    Signed-off-by: Georg Kunz <georg.kunz@ericsson.com>
    (cherry picked from commit 1fd3cba27f960f7ed10968afb437eaa412bda82b)

diff --git a/docs/submodules/netready b/docs/submodules/netready
index 4042107..bec6f09 160000 (submodule)
--- a/docs/submodules/netready
+++ b/docs/submodules/netready
@@ -1 +1 @@
-Subproject commit 4042107009da73955e87401218583f80375fcd30
+Subproject commit bec6f09efda840a7bb15810b40635b4e8ec4cf63