audioreactive: workaround for ArduinoFFT bug 93

This fix works around a problem that was solved in upstream ArduinoFFT 2.0.2

usermods/audioreactive/audio_reactive.h

@@ -282,6 +282,7 @@ void FFTcode(void * parameter)
       //FFT.windowing(FFTWindow::Blackman_Harris, FFTDirection::Forward);  // Weigh data using "Blackman- Harris" window - sharp peaks due to excellent sideband rejection
       FFT.compute( FFTDirection::Forward );                       // Compute FFT
       FFT.complexToMagnitude();                                   // Compute magnitudes
+      vReal[0] = 0;   // The remaining DC offset on the signal produces a strong spike on position 0 that should be eliminated to avoid issues.
 
       FFT.majorPeak(&FFT_MajorPeak, &FFT_Magnitude);                // let the effects know which freq was most dominant
       FFT_MajorPeak = constrain(FFT_MajorPeak, 1.0f, 11025.0f);   // restrict value to range expected by effects