Update ms2 submodule.

[linphone] / mediastreamer2

diff --git a/mediastreamer2 b/mediastreamer2
index 256e4eca87c06865d0ff186d05b4ca03f9394701..8cb156754fb5fa67365ecc36c0523e5914fd7ce7 160000 (submodule)
--- a/mediastreamer2
+++ b/mediastreamer2
@@ -1 +1 @@
-Subproject commit 256e4eca87c06865d0ff186d05b4ca03f9394701
+Subproject commit 8cb156754fb5fa67365ecc36c0523e5914fd7ce7