Fixed crash when changing audio input with FFT debug window

CaseLights/AppDelegate.m

     // Stop previous audio data retrieval
     if (microphone != nil) {
         [microphone stopFetchingAudio];
-        microphone = nil;
     }
     
     // Remove display callback
     // Stop previous audio data retrieval
     if (microphone != nil) {
         [microphone stopFetchingAudio];
-        microphone = nil;
     }
     
     // Turn off all other LED menu items
         // Stop previous audio data retrieval
         if (microphone != nil) {
             [microphone stopFetchingAudio];
-            microphone = nil;
         }
 
         // Turn off all other LED menu items
     // Stop previous audio data retrieval
     if (microphone != nil) {
         [microphone stopFetchingAudio];
-        microphone = nil;
     }
     
     // Schedule next invocation for this animation...
     // Stop previous audio data retrieval
     if (microphone != nil) {
         [microphone stopFetchingAudio];
-        microphone = nil;
     }
     
     // Schedule next invocation for this animation...
                 foundDev = YES;
                 if (microphone != nil) {
                     [microphone stopFetchingAudio];
-                    microphone = nil;
+                } else {
+                    microphone = [EZMicrophone microphoneWithDelegate:self];
                 }
-                microphone = [EZMicrophone microphoneWithDelegate:self];
                 [microphone setDevice:dev];
                 [microphone startFetchingAudio];
                 break;
                 // Stop previous audio data retrieval
                 if (microphone != nil) {
                     [microphone stopFetchingAudio];
-                    microphone = nil;
                 }
                 
                 NSColor *color = [staticColors valueForKey:key];

CaseLights/AudioVisualizer.m

 //  Copyright © 2016 xythobuz. All rights reserved.
 //
 
-// Enabling this will cause crashes when changing audio input
-// devices while the app is running. Select it before enabling.
 #ifdef DEBUG
 #define DEBUG_PLOT_FFT
 //#define DEBUG_PLOT_FFT_RAW

CaseLights/Info.plist

 	<key>CFBundleSignature</key>
 	<string>????</string>
 	<key>CFBundleVersion</key>
-	<string>388</string>
+	<string>391</string>
 	<key>LSApplicationCategoryType</key>
 	<string>public.app-category.utilities</string>
 	<key>LSMinimumSystemVersion</key>