message: sdp: add missing continue after parsing b= lines
  otherwise this shows up in the logs as unhandled when it has been handled.
  Cr-Commit-Position: refs/heads/master@{#32810}
diff: @@ -3059,6 +3059,7 @@ bool ParseContent(const std::string& message,
  }
  media_desc->set_bandwidth(b);
  media_desc->set_bandwidth_type(bandwidth_type);
  + continue;
  }
  // Parse the media level connection data.
  