Add fmtp parameters to opus payload to enable FEC and DTX

[linphone] / mediastreamer2

diff --git a/mediastreamer2 b/mediastreamer2
index ef59e93709972e8e7ed1a4b642f0c113b575916f..2278eb3fca4601bd5911f1fe9585d0a3f643f965 160000 (submodule)
--- a/mediastreamer2
+++ b/mediastreamer2
@@ -1 +1 @@
-Subproject commit ef59e93709972e8e7ed1a4b642f0c113b575916f
+Subproject commit 2278eb3fca4601bd5911f1fe9585d0a3f643f965