Aac-eld add missing header according to RFC3640 3.3.6

diff --git a/mediastreamer2 b/mediastreamer2
index c3e5bad583aad848e1e0d5391092311a31f3ea5a..bec2520cbb80daf9420bf71c05e25394e2b6024d 160000 (submodule)
--- a/mediastreamer2
+++ b/mediastreamer2
@@ -1 +1 @@
-Subproject commit c3e5bad583aad848e1e0d5391092311a31f3ea5a
+Subproject commit bec2520cbb80daf9420bf71c05e25394e2b6024d