message: Audio - Mixer conceptual documentation: fix footnote
  NOTRY=true
  Cr-Commit-Position: refs/heads/master@{#33934}
diff: @@ -24,9 +24,8 @@ muted state) and it is identified by an SSRC[^1].
  is used to retrieve the next 10 ms chunk of audio to be mixed.
  [^1]: A synchronization source (SSRC) is the source of a stream of RTP packets,
  -
  -identified by a 32-bit numeric SSRC identifier carried in the RTP header so as
  -not to be dependent upon the network address (see
  + identified by a 32-bit numeric SSRC identifier carried in the RTP header
  + so as not to be dependent upon the network address (see
  [RFC 3550](https://tools.ietf.org/html/rfc3550#section-3)).
  ## AudioMixer
  