Update oRTP submodule.

[linphone] / oRTP

diff --git a/oRTP b/oRTP
index 35f5efbfbf7814bd0403249431a6b94d6c4286b4..9f51aa254fc5c24834614612036485406a8d06a7 160000 (submodule)
--- a/oRTP
+++ b/oRTP
@@ -1 +1 @@
-Subproject commit 35f5efbfbf7814bd0403249431a6b94d6c4286b4
+Subproject commit 9f51aa254fc5c24834614612036485406a8d06a7