Update ms2 submodule for NEON detection fix.

[linphone] / mediastreamer2

diff --git a/mediastreamer2 b/mediastreamer2
index 4ad5b7becb57b10775d024f89140c8c462c9de57..239be1a39fa3f4ab460e8e7ab6d4d3d31e15e72a 160000 (submodule)
--- a/mediastreamer2
+++ b/mediastreamer2
@@ -1 +1 @@
-Subproject commit 4ad5b7becb57b10775d024f89140c8c462c9de57
+Subproject commit 239be1a39fa3f4ab460e8e7ab6d4d3d31e15e72a