Fix incorrect rtx config in full_stack tests.

BUG=4326
R=pbos@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/40819006

Cr-Original-Commit-Position: refs/heads/master@{#8455}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 343096ac03bfb0e1cadbcead29ce925522c12d5b
1 file changed