Always ResetSenderCongestionControlObjects before RegisterEtc...

BUG=webrtc:7896

Review-Url: https://codereview.webrtc.org/2966503002
Cr-Commit-Position: refs/heads/master@{#18844}
diff --git a/webrtc/audio/audio_send_stream.cc b/webrtc/audio/audio_send_stream.cc
index f8ee3ab..36ad63d 100644
--- a/webrtc/audio/audio_send_stream.cc
+++ b/webrtc/audio/audio_send_stream.cc
@@ -171,7 +171,7 @@
   // Transport sequence number
   if (first_time ||
       new_ids.transport_sequence_number != old_ids.transport_sequence_number) {
-    if (old_ids.transport_sequence_number) {
+    if (!first_time) {
       channel_proxy->ResetSenderCongestionControlObjects();
       stream->bandwidth_observer_.reset();
     }