add special case to compute aac network birate

[linphone] / oRTP

diff --git a/oRTP b/oRTP
index 20b527144f9850dd9065d96db7a20244e8a8b227..bd64df5148bdfd4a2ff5153927676fc497118279 160000 (submodule)
--- a/oRTP
+++ b/oRTP
@@ -1 +1 @@
-Subproject commit 20b527144f9850dd9065d96db7a20244e8a8b227
+Subproject commit bd64df5148bdfd4a2ff5153927676fc497118279