set port expander by default for Mini-4-Layer board

src/settings.h

@@ -31,7 +31,7 @@
 
 
 	//########################## MODULES #################################
-	//#define PORT_EXPANDER_ENABLE          // When enabled, buttons can be connected via port-expander PCA9555 (https://forum.espuino.de/t/einsatz-des-port-expanders-pca9555/306)
+	#define PORT_EXPANDER_ENABLE          // When enabled, buttons can be connected via port-expander PCA9555 (https://forum.espuino.de/t/einsatz-des-port-expanders-pca9555/306)
 	//#define I2S_COMM_FMT_LSB_ENABLE       // Enables FMT instead of MSB for I2S-communication-format. Used e.g. by PT2811. Don't enable for MAX98357a, AC101 or PCM5102A)
 	#define MDNS_ENABLE                     // When enabled, you don't have to handle with ESPuino's IP-address. If hostname is set to "ESPuino", you can reach it via ESPuino.local
 	//#define MQTT_ENABLE                   // Make sure to configure mqtt-server and (optionally) username+pwd