message: AudioFilterbank.h: Use getPrefix() from SerialManager_UI
diff: @@ -460,7 +460,7 @@ void AudioFilterbank_UI::printChanMsg(int direction) { //direction +1 is up, -1
  void AudioFilterbank_UI::printHelp(void) {
  - Serial.println(F(" Filterbank: Prefix = ") + String(quadchar_start_char) + String(ID_char) + String("x"));
  + Serial.println(F(" Filterbank: Prefix = ") + getPrefix()); //getPrefix() is in SerialManager_UI.h, unless it is over-ridden in this class somewhere
  printChanMsg(1); //upward changes
  printChanMsg(-1); //downward changes
  }
  @@ -468,7 +468,7 @@ void AudioFilterbank_UI::printHelp(void) {
  bool AudioFilterbank_UI::processCharacterTriple(char mode_char, char chan_char, char data_char) {
  //check the mode_char to see if it corresponds with this instance of this class. If not, return with no action.
  - if (mode_char != ID_char) return false;
  + if (mode_char != ID_char) return false; //ID_char is from SerialManager_UI.h
  //check to see if we have filters configured. If not, return;
  int n_crossover = (this_filterbank->state.get_n_filters()) - 1;
  