fix for ADC analog

the "wait until I2S buffer fills" trick does not work for ADC sources, as the I2S sampling does not run in background for ADC.

usermods/audioreactive/audio_reactive.h

@@ -411,8 +411,11 @@ void FFTcode(void * parameter)
     // run peak detection
     autoResetPeak();
     detectSamplePeak();
-
-    vTaskDelayUntil( &xLastWakeTime, xFrequency);        // release CPU, and let I2S fill its buffers
+    
+    #if !defined(I2S_GRAB_ADC1_COMPLETELY)    
+    if ((audioSource == nullptr) || (audioSource->getType() != AudioSource::Type_I2SAdc))  // the "delay trick" does not help for analog ADC
+    #endif
+      vTaskDelayUntil( &xLastWakeTime, xFrequency);        // release CPU, and let I2S fill its buffers
 
   } // for(;;)ever
 } // FFTcode() task end