Updated git submodules

Project: releng/builder master 869ddaf892cbf801893238773557d760aa5aa74a

Merge "Default generic mininet to mininet-ubuntu"

Default generic mininet to mininet-ubuntu

Mininet only runs on Ubuntu nodes now. This change is needed for Heat as
it does not currently provide a OS name in the node name to properly
detect the spinup script.

Change-Id: I3247b14d21a95ad8b55d04ac8eb361831c4929ab
Signed-off-by: Thanh Ha <thanh.ha@linuxfoundation.org>

diff --git a/docs/submodules/releng/builder b/docs/submodules/releng/builder
index 3ad73753e521e611eca9e5cb2e64277c80eb6eda..869ddaf892cbf801893238773557d760aa5aa74a 160000 (submodule)
--- a/docs/submodules/releng/builder
+++ b/docs/submodules/releng/builder
@@ -1 +1 @@
-Subproject commit 3ad73753e521e611eca9e5cb2e64277c80eb6eda
+Subproject commit 869ddaf892cbf801893238773557d760aa5aa74a