added unregisterReceiver(usbReceiver) to onDestroy()

examplestreams/src/main/java/com/felhr/examplestreams/UsbService.java

@@ -126,6 +126,7 @@ public class UsbService extends Service {
     @Override
     public void onDestroy() {
         super.onDestroy();
+        unregisterReceiver(usbReceiver);
         UsbService.SERVICE_CONNECTED = false;
     }
 
@@ -293,4 +294,4 @@ public class UsbService extends Service {
             this.keep.set(keep);
         }
     }
-}
+}